Research with Finnsheep

Transcription

1 I j, I Agriculture Cnd Reserch Brnch Direction generte de l recherche Technicl Bulletin E Reserch with Finnsheep in Cnd * ' - * Cnd

2 Digitized by the Internet Archive in 2011 with funding from Agriculture nd Agri-Food Cnd - Agriculture et Agrolimentire Cnd

3 Reserch with Finnsheep in Cnd M. H. FAHMY Reserch Sttion, Agriculture Cnd Lennoxville, Quebec Technicl Bulletin E Reserch Brnch Agriculture Cnd 1991

4 Copies of this publiction re vilble from Reserch Sttion Agriculture Cnd, Reserch Brnch 2000 Route 108 Est F. O Box 90 Lennoxville, Quebec JIM 1Z3 Produced by Reserch Progrm Service Minister of Supply nd Services Cnd 1991 Ct. No. A54-8/1991-2E ISBN Eglement disponible en frncis sous le litre Etude de l rce ovine Finnoise u Cnd Cover illustrtion The dots on the mp represent Agriculture Cnd reserch estblishments.

5 21 CONTENTS ACKNOWLEDGMENTS. v FOREWORD SUMMARY/RESUME vi vii 1. INTRODUCTION.1 2. ORIGIN OF FINNSHEEP 1 2. Erly history.1 2. Recent history History of Finnsheep in Cnd History of reserch with Finnsheep in Cnd 2 3. MARITIMES Nov Scoti Agriculturl College, Truro, Nov Scoti Mthewson, Mynrd nd McKenzie (1986) 3 4. QUEBEC Reserch Sttion, Lennoxville Fhmy (1979) Fhmy (1983) Fhmy (1985) Fhmy (1987) Fhmy nd Dufour (1988) Fhmy (1989) Fhmy (1989b) Fhmy, Flipot, Wolynetz nd Comeu (1989) Fhmy (1990) Fhmy (1990b) Fhmy, Boucher, Poste, Gregoire, Butler nd Comeu (1991) Lvl University, Ste. Foy Lirette, Seone, Minvielle nd Froehlich (1984) Chiquette, Minvielle nd Dufour ( 1984) Cstonguy, Minvielle nd Dufour (1990) Cstonguy, Dufour, Minvielle nd Estrd (1990b) ONTARIO Animl Reserch Centre, Ottw Wlton nd Robertson (1974) Shresth, Peters nd Heney (1982) Shresth, Fiser, Lngford nd Heney (1983) Bernon nd Shresth (1984) Shresth, Heney, Fiser nd Lngford (1984) Hckett nd Wolynetz 1985) Shresth nd Vesely (1986) Ainsworth nd Shresth (1987) Ivn (1988) Shresth nd Heney (1990) 34 in

6 6. MANITOBA University of Mnitob, Winnipeg Snford, Plmer nd Howlnd (1977) Snford, Beton, Howlnd nd Plmer (1978) Kennedy nd Belluk (1987) SASKATCHEWAN University of Ssktchewn, Ssktoon Jeffcote, Rwlings nd Howell (1984) Rwlings, Jeffcote nd Howell (1987) Rwlings (1987) ALBERTA 9. REFERENCES 10. AUTHOR 11. SUBJECT Reserch Sttion, Lethbridge Vesely (1978) Mukhoty nd Peters (1982) Vesely nd Swierstr (1985) Vesely nd Swierstr ( ) McClellnd (1989) INDEX 50 INDEX 51 IV

7 ACKNOWLEDGMENTS The uthor wishes to express his gret pprecition to Mrs. Suznne Ggne- Giguere for her devoted ssistnce in reviewing the literture nd revising the mnuscript. He is lso thnkfull to Miss Louise Boisvert for her exceptionl effort in typing, structuring nd formtting this bulletin. v

8 FOREWORD Sheep my be the first domesticted nimls in the history of mnkind. Biblicl stories with reference to sheep re numerous nd the mjority of Prophets were reported to hve rised sheep. In mny prts of the world sheep re still rised the sme primitive wy used by our ncestors centuries go. During the 18 th nd 19 th century mny new breeds of sheep were developed with emphsis on improving conformtion, wool nd met production. Little ttention ws pid to improving prolificcy. However, the need to intensify sheep production to conform to tody's systems of concentrted frming necessitted the use of prolific sheep to increse returns per unit of production. Until recently, little hs been known on the existence of such prolific breeds since they re found in rther remote loctions nd were rrely studied. Finnsheep ws the first breed to be recognized s prolific nd probbly no one single breed hs revolutionized sheep production s did the Finnsheep. In 1991, Finnsheep will hve been in Cnd for 25 yers. It ws thought proper to celebrte this occsion with this document summrising the Cndin contribution to reserch with tht breed. In this review, ech study ws summrized to highlight the role of, or the results obtined by the Finnsheep. Mny irrelevnt detils were eliminted. The studies were grouped by institution ccording to n Est to West geogrphic distribution. A subject index ws prepred to mke n esy reference to different studies working on the sme subject. The review ends with bibliogrphy of ll the rticles presented in this review. The uthor mde intensive efforts to collect ll Cndin scientific publictions on Finnsheep, if however, some references escped his ttention, he pologizes for this oversight. VI

9 SUMMARY Since its importtion into Cnd in 1966 the Finnsheep breed hs been involved in numerous reserch projects to study its performnce s pure breed nd evlute its crosses with other domestic sheep breeds. Most of the studies were conducted t three centers, nmely, the Lennoxville nd Lethbridge Reserch Sttions nd Animl Reserch Centre of Agriculture Cnd. Other institutions working on the Finnsheep hs been the universities of Lvl, Mnitob nd Ssktchewn. The studies demonstrted the dvntge in reproductive trits brought bout by using Finnsheep nd/or Finnsheep crosses. Studies on crcss evlution indicted tht Finnsheep crcsses, lthough slightly inferior in qulity s compred to met- type breeds hve been cceptble by consumers. Studies lso showed how Finnsheep nd its crosses dpt to different intensive systems of mngement. Finnsheep were lso involved in developing two new Cndin breeds nmely the Arcott Outouis nd Rideu. RlSUMF, Depuis 1 ' importtion u Cnd en 1966 de l rce ovine Finnoise, plusieurs etudes ont ete relisees fin d'etudier les performnces de l rce pure et d'evluer ses croisements vec les utres rces domes tiques. L pluprt des etudes ont ete effectuees dns trois centres de recherches d'agriculture Cnd, Lennoxville, Lethbridge et u Centre de recherches zootechniques Ottw. D' utres recherches ont ete effectuees l'universite Lvl, l'universite du Mnitob et l'universite de l Ssktchewn. Les etudes ont demontre l superiority de l rce Finnoise et de ses croisements pour les crcteres de reproduction. Les etudes sur 1' evlution des crcsses ont demontre que, meme si l qulite des crcsses des moutons de rce Finnoise est legerement inferieure celle des rces de boucherie, l vinde des moutons de rce Finnoise est bien cceptee pr les consommteurs. Les etudes ont eglement demontre que les moutons de rce Finnoise et ses croisements s'dptent bien ux differents systemes intensifs de regie. L rce Finnoise eglement contribue u developpement de deux nouvelles rces cndiennes, 1 'Arcott Outouis et Rideu. VII

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11 1. INTRODUCTION Although the Finnsheep breed hs been estblished in Finlnd for centuries, its "discovery" by the rest of the world goes bck to only During csul converstion with Dr. Klle Mijl, Finnish geneticist, scientists t the Animl Breeding Reserch Orgniztion in Edinburgh, Scotlnd lerned of its existence nd becme interested in cquiring some of these prolific sheep. Following the publiction of the results on the performnce of Finnsheep in Britin, mny countries becme interested nd the importtion wve of these sheep strted. Over the yers, Finnsheep hve been introduced to over 40 countries ll over the world including Cnd. Studies on Finnsheep prior to 1963 received little ttention nd redership becuse they were written in Finnish nd published in locl journls. However, fter the wide expnsion, the Finnsheep becme probbly one of the most studied breed in the literture. A survey of the rticles published nd bstrcted in Animl Breeding Abstrcts reveled tht performnce of pure Finnsheep nd crossbreeding studies with Finnsheep were reported in over 250 publictions since Cnd hs hd its shre of reserch with the Finnsheep which ws concentrted in few centers. The University of Mnitob, the first to import the breed, worked on crossing the Finnsheep with Rmbouillet, Suffolk nd synthetic line. Animl Reserch Centre used Finnsheep to develop two dm line strins with Finnsheep contributing up to 50% of the ncestry. The Lennoxville Sttion crossed Finnsheep with the DLS breed to produce different combintions. Other institutes used Finnsheep either in crossbreeding progrms (Lethbridge Sttion) or s n niml model (University of Ssktchewn) to test different nutritionl nd physiologicl tretments. 2.1 Erly history 2. ORIGIN OF FINNSHEEP In recent publiction, Mijl (1988) reported on the origin of the Finnsheep (F) in Finlnd. The following re extrcts from his rticle. Very little fcts re vilble bout the erlier history of F nd lso of sheep s frm nimls in Finlnd. It hs been climed by historins tht sheep hve been kept in Finlnd since the lter Iron Age. There re two lterntive min hypotheses concerning the source of F: est or west. The estern origin is supported by the fct tht the rrivl of Finns to Finlnd is climed to hve tken plce from the re of present Soviet Union t the beginning of the first millenium A.D. It cn be ssumed tht they hd the ncestors of F with them nd tht their reltives which styed in the northcentrl Russi my hve hd ncestors of Romnov breed which is lso shorttiled nd prolific nd hs some other common fetures with F. For the western origin, the fct is tht short- tiled ntive breeds occur in ll the other Scndinvin countries nd in some other prts of Northern Europe. Newer theories consider tht Finlnd got its inhbitnts prtly from the west. It is nturl to ssume tht these people lso brought frm nimls with them. It is generlly believed tht Finlnd hs received its sheep good thousnd yers go from its southern nd western neighbours, nd tht the breed

12 . 3 descends from the Mouflon sheep. Finnish sheep husbndry long served minly home needs of wool nd furs hence the nimls were kept in very smll self-sufficiency flocks. Met ws n importnt by-product. Ewes were lso milked. The production system my hve ffected selection nd mting systems. Close inbreeding my hve been common. It cn be ssumed tht the biggest rm lmbs, probbly born s singles, were slughtered for met erly in the utumn, while the smll ones from big litters were sved for further growth nd thus llowed to breed the ewes. This could be one lterntive explntion to the mintennce of high prolificcy. In mny other countries where sheep were economiclly importnt for the owner, rms were selected on the bsis of their size, nd hence minly from single-born lmbs. 2.2 Recent history More is known bout Finnish sheep husbndry from the 16th century onwrds. The Swedish king Gustv Vs tried to widen nd revive it by hving big sheep flocks on his royl esttes nd by importing foreign breeds. In the middle of the 18th century the government imported Merino sheep nd tried to expnd it, in order to develop textile industry. The impct of the importtions on the ntive sheep remined smll. 2. History of Finnsheep in Cnd The first exporttion of Finnsheep from Finlnd took plce in 1962 with the importtion by Scotlnd of 10 ewes nd five rms. Selection of the nimls ws mde minly on their record of fertility. Most sheep were born in lrge litters nd little ttention ws pid to body size or ny other trit. The first Cndin importtion ws mde in 1966 by the University of Mnitob. Four rms nd eight ewes born in 1966 from nimls previously imported by Scotlnd were the source of the Finnsheep in Cnd. Progeny of these nimls were moved to Ontrio (Animl Reserch Centre), Quebec (Lvl University) nd USA (Met Animl Reserch Center) for reserch purposes nd mny were sold to sheep breeders. 2 4 History of Reserch with Finnsheep in Cnd An undted 10-pge mimeogrph written round 1972 by Dr. M.E. Sele of the University of Mnitob entitled: "Evluting the Finnish Lndrce breed of sheep" is probbly the first written document on the performnce of Finnsheep in Cnd. Growth, prolificcy, wool chrcteristics nd crcss mesurements, during the yers were compred between Finnsheep, Finnsheep crosses nd other breeds nd their crosses. The uthor lso projected the role of the Finnsheep breed in Cnd nd its possible effect on the sheep industry.

13 3. MARITIMES 3.1 Nov Scoti Agriculturl College, Truro, Nov Scoti Mthewson, Mynrd nd McKenzie (1986) used Finnsheep x N.C. Cheviot, Suffolk x N.C. Cheviot, Hexhm Leicester x N.C. Cheviot nd Western ewes to compre two systems of mngement: trditionl, where ewes lmbed in spring nd nursed their lmbs on psture, or intensive where lmbing ws scheduled ech eight months under complete confinement nd following light control system. The results (Tble 1) indicted tht little differences between genetic groups in lmbing rte were observed under the trditionl system, while under the intensive system the Finnsheep cross showed the lowest lmbing rte. Ewes were slightly more fertile under the trditionl compred to the intensive system. The number of lmbs mrketed per ewe exposed per yer under the trditionl system verged 1.26 compred to 1.72 under the intensive system. Finnsheep cross hd the highest productivity under either system, the differences were however, smll. Lmb mortlity on trditionl system (18%) ws slightly higher thn on the intensive system (15%). Little differences were observed mong genetic groups in lmb mortlity. Tble 1. Performnce of ewes of four genetic groups under two mting systems Lmbing system & genetic groups Fertility Produc- Lmb Cost/ Revenue/ tivityf mortlity ewe $ ewe $ Trditionl Finnsheep x NCC Suffolk x NCC Leicester x NCC Western Men Intensive Finnsheep x NCC Suffolk x NCC Leicester x NCC Western Men f Lmb mrketed/ewe exposed, NCC - N.C. Cheviot.

14 4.1 Reserch Sttion, Lennoxville 4. QUEBEC At Lennoxville, Finnsheep were used minly in crossbreeding progrm with DLS sheep. Different combintions of Finnsheep -DLS were produced rnging from 1/8F 7/8 DLS (1/8F) to 7/8F 1/8 DLS (7/8F). The source of the F sheep ws the flock of Animl Reserch Centre in Ottw Fhmy (1979) published the results of study compring body nd crcss mesurements of DLS nd F x DLS lmbs slughtered t 23, 32 or 41 kg liveweight. Selected results re presented in Tble 2. Finnsheep cross grew t fster rte which resulted in younger ges t slughter nd hevier weights per dy of ge. The crossbred lmbs were longer nd hd lrger rounds when slughtered t 23 kg but were generlly smller thn the DLS lmbs t hevier slughter weights. Little differences were observed in the other crcss trits studied with the exception tht the crossbred lmbs were generlly ftter with less len thn pure DLS lmbs t ll three slughter weights. Tble 2. Body dimensions nd crcss mesurements of DLS nd Finnsheep x DLS lmbs slughtered t three body weights (8 lmbs per tretment) Genetic DLS Slughter weight (kg) groups Finnsheep x DLS Slughter weight (kg) Live mesurements Body length (cm) Hert girth (cm) Circumf. of round (cm) Crcss mesurements Dressing out (%) Leg (%) Loin- rck (%) Shoulder (%) 12th rib mesurements Ft thickness (mm) Loin- eye re (cm 2 ) Ether extrct (%) Ft (%) Bone (%) Muscle (%) Weight/dy of ge (g) The uthor concluded tht crcss of F cross with DLS ws not inferior to tht of DLS nd it compred firly well with crcss of other domestic breeds in Cnd.

15 Fhmy (1983) compred the mternl performnce of three F crosses with the DLS (1/4F, 1/2F nd 3/4F) to tht of pure DLS. The results (Tble 3) showed tht the four genetic groups were extremely fertile (between 96 nd 99%). The number of lmbs born nd wened incresed progressively with the increse in proportion of the F breed. The 3/4F group hd the highest prolificcy t birth (2.2 lmbs born), 75% higher thn DLS, but 0.3 lmbs (12%) of these lmbs died t birth or were born ded. The lowest mortlity t birth ws tht of 1/4 F cross t 3.6%. Of 1. 9 lmbs born live to 3/4F ewes, nother 0.3 lmbs (17%) died before wening. This high ntl nd prewening mortlity rte of 3/4F cross resulted in similr litter size t wening for 3/4F nd 1/2F ewes which ws significntly lrger thn in 1/4F nd DLS ewes (by 26 nd 50% respectively). Finnsheep crosses produced hevier litters t birth nd t wening thn DLS (between 6 nd 9% t birth, nd 11 nd 14% t wening). Dte of lmbing (following mting strting in June 1 to October 31) ws erliest in DLS followed by 1/4F, 1/2F nd 3/4F in tht order. The reltion ws liner between dte of lmbing nd proportion of F sheep breeding in the cross. Tble 3. Productivity of DLS nd Finnsheep (F)-DLS crosses nd superiority of the crosses (%) reltive to DLS Genetic groups Superiority of the crosses DLS 1/4F 1/2F 3/4F 1/4F 1/2F 3/4F No. of nimls Fertility (%) Lmbs born/litter totl Lmbs born/litter live Lmbs wened/litter b 2.15 c , b 1.92 c b 1.64 b Litter birth wt totl (kg) Litter birth wt live (kg) Litter wening wt (kg) Lmbing dte , l 30. l /12 30/12 b 7/01 c 15/01 c In this, nd in other tbles presented in this bulletin, mens followed by different letters re sttisticlly significntly different. The conclusion drwn from this study ws tht lthough F crosses my be decisively superior to locl breeds in prolificcy, however, when mesuring ewe productivity in terms of kilogrms of wened lmbs, the dvntge of the F crossing become less evident due to high mortlity nd slower growth rte of their lmbs Fhmy (1985) reported on popultion of 139 entire mle lmbs born in 1980 nd 1981 nd fed d libitum for eight weeks rtion of grss nd legume silge supplemented with grin mixture. The lmbs represented the DLS breed nd six of its crosses with the Finnsheep rnging from 1/8F to 6/8F. The lmbs were slughtered t bout 43 kg liveweight nd mesurements of length, hert

16 girth nd circumference of leg were tken on the chilled crcsses. The crcsses were then divided into leg, loin- rck nd shoulder cuts nd ech ws expressed s percentge of the whole weight. Kidney nd pelvic ft were seprted nd weighed. The 12th rib cut ws dissected into ft, bone nd muscle nd the percentge of ech ws clculted. The re of the two loin- eye muscles of the 12th rib nd three mesurements of bckft over tht muscle were mesured nd verged. The percent ft in the loin-eye muscle ws determined by ether extrction. Tble 4. Lest-squre mens for growth nd crcss chrcteristics of DLS nd the different crosses of Finnsheep (F) z DLS 6/8F 5/8F Genetic groups 4/8F 3/8F 2/8F 1/8F DLS No. of lmbs Weights nd gins Birth weight (kg) Wening weight (kg) Prewening ADG (g/dy) Gin on test (g/dy) Age t slughter (dy) Weight t slughter (kg) Crcss dimensions Body length (cm) Hert girth (cm) Leg circumference (cm) Crcss percentges Dressing (Z) Leg (Z) Loin (Z) Shoulder (Z) Kidney ft (Z) 12th rib mesurements Len (Z) Ft (Z) Bone (Z) Are of loin-eye muscle (cm 2 ) Ft over loin-eye muscle (mm) Ether extrct (Z) Feed conversion rtio 3.06 d 3.79 c 4.05 bc 3.41 c bc 4.37 b * l 128 b 119 b 114 b 122 b 119 b +3.6* b b b 42.2 b 44. l 41. b b d 32. d 32.8 cd b 32.8 cd S.IS** 2 99 bc bc 2.60 c 2.41 c 2.45 c +0.15** b b b b t * b Regression coefficient on proportion of F in the cross. Qudrtic regression, b 2 " -3.11*, b, 0.42** In this, nd in other tbles * nd ** refer to significnce (P<0.05 nd P<0.01, respectively). DLS nd 1/8F lmbs were the heviest t birth (Tble 4). Birth weight seemed to decrese lmost linerly with the increse in the proportion of the F breeding (b kg). Prewening verge dily gin rnged from 245 g (6/8F) to 271 g (4/8F), the differences being nonsignificnt. The differences mong the seven genetic groups in wening weight were lso smll nd nonsignificnt. The highest gins on test were mde by the 6/8F nd 5/8F crosses which were significntly higher thn the five other genetic groups. The youngest lmbs t slughter were from the 4/8F cross (243 dys) followed by DLS, 2/8F nd 6/8F lmbs (264 dys). The differences mong these genetic groups were, however, nonsignificnt.

17 . The feed conversion rtios were similr t bout 6.8. No consistent differences were observed mong the genetic groups though it my be mentioned tht the crosses were either equl to or slightly less efficient thn the pure DLS. DLS lmbs nd those from the six F crosses were very similr in crcss dimensions (Tble 4). Dressing percentges were rther low rnging from 41.2% for the 1/8F to 44.1% for the 2/8F, the difference being significnt. The present study demonstrted tht there were only slight differences, mostly nonsignificnt, in fvor of the crosses in dressing percentge. DLS nd 1/8F lmbs were more developed in the leg re, the differences in percent leg between these two genetic groups nd the other crosses being significnt. No significnt differences were observed between the genetic groups in percent loin or shoulder of the crcss. The percent of ft round the kidneys nd pelvis incresed grdully nd lmost linerly with the increse in the F proportion (b-0\149). The 4/8F cross hd the highest percentge of kidney nd pelvic ft (3.31%), which ws significntly different from DLS, 1/8F nd 2/8F crosses. DLS lmbs tended to hve more len nd bone nd less ft in the 12th rib thn the other crosses. Significnt differences were observed only in percent ft (Tble 4). The reltion between proportion of F in the cross nd ft percentge ws curviliner. The 4/8F cross ws gin the fttest followed by 5/8F nd 3/8F. No significnt differences mong the genetic groups were observed in the re of loin-eye muscle, verge ft thickness over the loin-eye muscle, or percent ft in the loin-eye-muscle (ether extrct nlysis) The uthor concluded from this study tht the chrcters which showed liner trend with the increse in F proportion were those relted to ft deposition in the body whether internlly, externlly or intrmusculrly. And tht, in generl, crosses with vrious portions of F breeding produce lmbs comprble in qulity to those from DLS popultion with no F ncestry Fhmy (1987) worked on wool production nd fleece chrcteristics of DLS, Finnsheep nd their crosses. The smples used were wool fibers grown on 2 cm 2 of skin removed from the shoulder region of 273 femle yerlings over period of three yers. The yerlings represented nine genetic groups, F, DLS nd seven combintions rnging from 1/8F to 7/8F. The trits studied were stple length, fiber density, clen wool percentge, fiber length nd thickness nd their vribility. Grese fleece weight (GFW) ws recorded t first shering on the 273 yerlings nd on n dditionl 90 femle yerlings. GFW ws subsequently recorded t yerly intervls up to the 5th shering. The results indicted tht F yerlings hd 1.4 cm longer stple nd 3. 3 cm longer fibers thn DLS yerlings (Tble 5). Vribility in fiber length ws significntly higher in F thn in ll the genetic groups studied (except for the 5/8F). Among the crosses, the 4/8F, 5/8F nd 6/8F hd the longest stple ( cm) nd wool fibers ( cm). The mens for these crosses were close to those for pure F (13.4 nd 19.1 cm, respectively). Lmbs sired by F rms or born to F ewes hd the highest vribility in fiber length nd fiber thickness. Fiber density ws 1551 fibers/cm 2 in DLS compred to 1950 fibers/cm 2 in F. It rnged in the crosses between 1642 fibers/cm 2 in 7/8F to 1856 fibers/cm 2 in 6/8F.

18 l 2 5 DLS yerlings hd the lowest percentge of clen wool (61.2). The differences were significnt with ll other genetic groups except 1/8F, 3/8F nd pure F (Tble 5). The highest percentge of clen wool ws shown by 7/8F (66.2) nd 4/8F (66.1), the differences with the other crosses were nonsignificnt. Finnsheep nd 7/8F yerlings hd fleeces with the finest fibers nd the lowest vribility in fiber thickness, wheres DLS yerlings hd the corsest fleeces with the highest vribility in fiber thickness mong the nine genetic groups (Tble 5). The difference of 5 /im between the yerlings of the two pure breeds ws highly significnt. Tble 5. Lest squres mens for wool production nd fleece chrcteristics of DLS, Finnsheep (F) nd crossbred yerlings Genetic groups DLS 1/8F 2/8F 3/8F 4/8F 5/8F 6/8F 7/8F No. of yerlings Stple length (cm) bc 13.9 bc 14. C ^ bc Fiber density/cm b 1740 b 1798 b 1675^ 1756^ 1856 b 1642 b 1950 b Clen wool (%) b 63.8 bc 63. e 3* l c l c 66. C 63.5^ Fiber length (cm) b 18.0 be 17.7 be 18.5 bc 19.2 cd 20. d 18.8 cd 19.1 cd Vribility in fiber length (cm) ^ bc 4.04 cd bc bc d Fiber thickness (tun) 25. d 23. C 23. d 23. bc 23. C 22.7 bc 22.2 bc 21. 5^ 20. Vribility in fiber thickness (/im) 5.9 b s 4.8* 1st shering (kg) b b 2. 18* 1.78 c 2.35* 2nd shering (kg) b 2.44 s 2.39 c 2.21 bc 2.16 b 1.84 d 2.02 bd 3rd shering (kg) 4-5th shering (kg) 2.81 b ^ ,78^ 2.58 cd 2.67 c 2.62 bc 2.39 ce 2.25 de 1.89 e c bcd 2.36 de 2.22 de 2.02 e Finnsheep nd the crossbred ewes with high proportion of F breeding were generlly lower in wool production thn DLS ewes nd ewes from crosses with high proportion of DLS breeding. Wool production generlly incresed with dvnce in ge. Most of the crosses showed positive heterosis in first nd second sherings nd ll the crosses showed high positive heterosis in third nd lter sherings. The highest expression of heterosis ws observed in the 4/8F nd 5/8F crosses (Tble 5). The fleeces of the 1/8F cross ewes were consistently hevier thn those of the DLS ewes. The reltionship between the proportion of F breeding nd grese fleece weight ws liner for the second shering nd curviliner for lter sherings. The regression nlyses of the trits studied on the proportion of F in the genetic group indicted tht the reltion ws liner for fiber thickness. The reltion ws lso liner for vribility in fiber thickness nd vribility in fiber length nd curviliner in clen wool percentge nd fiber length. The tendency ws for fiber thickness, nd its vribility, to decrese nd the

19 vribility in fiber length to increse with the increse in the proportion of F in the genetic group. The uthor concluded from the study tht crossing the DLS with F resulted in n improvement (often significnt) in wool production nd fleece chrcteristics in the crosses s compred to the DLS. Crosses with equl nd ner equl proportions of the two breeds (4/8F, 5/8F nd 3/8F) seem to be the best combintions between these two breeds for GFW nd wool chrcteristics Fhmy nd Dufour (1988) reported on reproductive performnce nd body weight of 361 ewes, representing Finnsheep, DLS nd seven combintions rnging from 1/8F to 7/8 F breeding. Dt were collected on conception rte, ovultion rte, gesttion length, prolificcy (number of lmbs born, born live nd wened), litter weight t birth nd wening, ov loss nd prewening lmb mortlity. Weight of lmbs t birth nd t wening nd ewe weight t lmbing were lso studied. Weight of lmbs wened per ewe exposed ws considered s representtive mesurement of overll ewe productivity. The results indicted tht only 61.5% of DLS yerlings exposed to rms t 7-8 months of ge conceived compred to 89.0% of F yerlings. This wide difference ws explined in prt by differences in ge t sexul mturity, F being n erly-mturing breed. This explntion ws lso supported by the progressive increse in conception rte in the crosses with n increse of F breeding. At lter prities, conception rtes were generlly high (vg. 94%) nd with few exceptions, similr in the different genetic groups. Differences between genetic groups were generlly smll, cross prities. Ovultion rte ws lowest in DLS nd 1/8F groups nd highest in F, 7/8F nd 6/8F groups (Tble 6). Ovultion rte incresed with ge from 2.36 t 1.5 to 2.64 nd 2.90 t 2.5 nd 3.5 yers of ge, respectively. DLS ewes verged 1.44 lmbs t birth of which 3% were born ded s compred to 2.86 lmbs nd 8% for F. Litter size t birth incresed progressively from 1.63 for 1/8F to 2.42 lmbs for 7/8F ewes. DLS ewes wened 1.22 nd F, 2.03 lmbs. The verges were 0.70 nd 1.68 t one yer of ge, respectively. Litter size t birth of ewes with 4/8F or higher F breeding ws significntly higher thn those with proportion lower thn 4/8F breeding (Tble 6). The difference in litter weight t birth between DLS, the lightest, nd F, the heviest group, ws 1.35 kg. Litter birth weight of the seven crosses ws intermedite (Tble 6). Averge birth weight of lmbs derived by dividing litter weight by the number of lmbs born (thus not djusted for sex or type of birth), showed tht the heviest lmbs born were to DLS ewes (4.15 kg) wheres lmbs from F ewes were the lightest (2.65 kg). At wening, the heviest litters were those rised by 4/8F ewes (31.7 kg) followed by 7/8F (30.8 kg), while those rised by DLS nd 2/8F ewes were the lightest, the differences being significnt (Tble 6). Prewening verge dily gin of lmbs rnged between 182 g for F to 217 g for those rised by 4/8F nd 1/8F ewes. Lmb wening weight ws similr for DLS, 1/8F, 2/8F, 3/8F, nd 4/8F groups, 1 to 2 kg hevier thn those rised by 5/8F, 6/8F nd 7/8F ewes. Finnsheep -rised lmbs were the lightest t wening, weighing 15.4 kg.

20 l l Number of ov not resulting in lmbs per ewe mted vried in different genetic groups nd rnged from 18.2% in 1/8F to 29.4% in 6/8F crosses (Tble 6). Crosses with F exceeding 2/8F, lost between 26.0 nd 29.4% of their ov, in spite of the wide differences observed between these crosses in ovultion rte. About 3.6% of ll lmbs born were either born ded or died within few hours fter birth nd further 13.8% died before wening (Tble 6). The high proportion of lmbs born ded ws observed for 6/8F ewes (5.2%) wheres the lowest rte (0.8%) ws observed in the 5/8F group. Prewening mortlity rte ws highest (22.9%) in F nd lowest in 3/8F group (9.4%). Averge gesttion period of DLS ewes ws dys, one dy longer thn tht of F, 7/8F nd 3/8F ewes (Tble 6). Gesttion period of 6/8F ewes ws dys, wheres 1/8F ewes crried their litters for dys. Averge number of lmbs wened per ewe mted extended from 1.89 (F) to 1.06 (DLS) weighing from 27.6 kg (4/8F) to 18.1 kg (DLS). Tble 6. Lest squres mens for the reproductive trits studied ccording to genetic group Genetic groups DLS 1/8F 2/8F 3/8F 4/8F 5/8F 6/8F 7/8F F Conception rte 86. C gl 3 bc 95.6 b 90. bc 97. 2^ bc g2 ]bc 96.0 bc Ovultion rte b 2.45 bc 2.68 c 2.88 cd 3.22 d 3.26 d 3.42 d Litter size t birth b 1.67 bc 1.81 c 2.12 de 2.05 d 2.26 e 2.42 f 2.86^ Litter size t wening b 1.45 b 1.52 b 1.84 cd 1.76 cd 1.69 c 1.91 cd 2.03 d Litter wt t birth (kg) c 6.26 c 6.56 bc 6.37 bc bc 7.10 c Litter wt t wening (kg) cf 24 b bc e 29.4 def 28.5 cd def 29.1 cde Avg. lmb birth wt (kg) b 3.87 b 3.68 c 3.28 d 3.25 d 2.97 e 2.96 de 2.65 e Avg. lmb wening wt (kg) 18.4 b b 18.3 b 18.5 b 17.3 bc C C C Ov loss/ovultion (Z)f b 26.0 b 26.5 b 26 b b b 26 b. Ov loss/ovultion (Z)\ 9.2 b bc C C C C C Lmbs born ded/born (Z)f 3.04 b b b b 8.02 Lmbs ded before wening/ totl born live (X)\ b b b b 17 b b Gesttion length (d) b c C bc c C bc 145. bc No. of lmbs wened b 1.36 b 1.34 b c 1.45 b 1.74 c 1.89 c kg of lmbs wened 18. l b b b C C b 25.5 bc 26.0 bc f, Per ewe mted nd per ewe exposed, respectively. F Finnsheep. At first lmbing, F ewes weighed 43.7 kg, 7. 8 kg hevier thn DLS ewes. This difference in weight disppered with ge nd t five yers of ge DLS ewes were 4.5 kg hevier (61.9 vs kg). The heviest ewes t one yer were the 4/8F verging 45.5 kg wheres the lightest were the 7/8F ewes (36,1 kg). The heviest mture weights were those of 3/8F nd 4/8F crosses (66.4 n 65.5 kg, respectively), however the differences with other crosses were rther smll. The 4/8F cross showed the highest heterosis in litter size n litter nd lmb weights t wening nd the second highest heterosis in ovultion nd conception rtes (Tble 6). Ewes from 4/8F group produced 25% more kilogrms of lmbs t wening thn the verge of their prentl breeds. Significnt positive liner regressions were found for ovultion rte, litter size t birth nd wening nd prewening mortlity rte, indicting tht these trits incresed progressively with increse in F proportions. On the other hnd, significnt negtive liner reltionships were found for verge lmb weight t birth nd t wening suggesting the opposite tendency. 10

21 .. Significnt qudrtic reltionships were clculted for percent of ov lost, lmb mortlity t wening nd weight of ewe t lmbing. Crosses with low proportions of F (1/8F to 3/8F) produced 22 kg of lmbs wened, those with higher proportions (5/8F to 7/8F) produced bout 24.5 kg, wheres the 4/8F cross gve the highest performnce (27.6 kg). The uthors concluded tht ech increse of 1/8 breeding contributed by F resulted in 0.24 increse in number of ov shed. However, over 25% of these ov were lost in genetic groups with 3/8 nd higher F breeding. The reltion between F breeding nd litter size t birth ws liner. Prewening mortlity rte ws similr in crosses with 1/8F to 4/8F breeding nd incresed mrkedly with the increse in F breeding bove 5/8. The 4/8F cross showed mrked superiority in litter size t wening (51% over DLS) The 4/8F cross exhibited the highest performnce in litter weight t wening. Compred to the theoreticl expecttions, the two crosses closest to the prentl breeds (1/8F nd 7/8F) were generlly superior to the two crosses closest to the F., (3/8F nd 5/8F), wheres the two bckcrosses (2/8F nd 6/8F) rnked lowest Fhmy (1989) collected dt on growth nd crcss on 252 multiple -born lmbs representing 11 genetic groups, fed either high-energy minly concentrte rtion or low- energy minly roughge rtion nd slughtered t either 32 or 41 kg liveweight. The lmbs were the progeny of Suffolk rms mted to Suffolk (S), F, DLS ewes nd ewes from seven F-DLS crosses rnging between 1/8F to 7/8F in ddition to DLS x DLS lmbs. Lmbs produced by crossing S rms with DLS, F nd the seven crosses between DLS nd F rnged between 195 nd 226 g/dy in verge dily gin (ADG) to 32 kg liveweight (Tble 7). The differences mong genetic groups were generlly smll nd nonsignificnt. Growth rte from 32 to 41 kg liveweight ws highest in lmbs from 7/8F ewes followed by those from 3/8F ewes (262 nd 256 g/dy, respectively) Dressing percentge rnged from 43.2% in S to 46.6% in S x F lmbs nd ws generlly similr in crosses with differing proportions of DLS nd F breeding in the dm (Tble 7). The proportion of shoulder vried within limited rnge in the different genetic groups. As expected, lmbs from F ewes hd the highest percentge of kidney nd pelvic ft (4.1%). DLS lmb hd higher kidney ft percentge thn ll but one F cross (Tble 7). Suffolk lmbs hd the highest percentge of len nd bone nd the lowest percentge of ft in the 12th rib nd thinner ft cover over tht rib, s compred to the other genetic groups. They lso hd the drkest loin-eye muscle color. The re of loin-eye muscle ws lrgest in S x DLS lmbs (12.6 cm 2 ) nd smllest in S x 6/8F (10.6 cm 2 ) lmbs. The re rnged between 11.1 to 11.6 cm 2 ) in the other genetic groups. Significnt liner regressions of trits on proportion of F breeding in the dm of the lmb were observed for leg percentge (b -0.18) loin- rck percentge (b=0.16), percent kidney ft (b=0.12), re of loin-eye (b--0.16) nd color of loin-eye muscle (b--0.07). Lmbs with F ncestry were vlued between $153 (2/8F) nd $165 (4/8F) nd those of pure S $156 (Tble 7). Returns per ewe 11

22 1 1 1' 1 L, i 1 0] 3 o 5-1 bo 4J <D c bo 4J C 0) U 0) iw 4-1 rc u u o Cm w c CO 0) s 0) 1-1 CO 3 cr u] u 0] cd 0) is H H O /-s cm co Cm s-' to CO co Ct, f co co En CO CO VO f CO CO \m f co co f co co \CO f CO CO CM f co co CO f- CO O XJ jd «O CM IS rh ON Z2 VO CM vo g* CM 1Q rh CO CO on rh A O- >«_ CO CO CO CM co m r*^ vo cm r*» ON rh qo rh fo vo vo r-* vo in CO is co i 1 CO O 4 CO CM CO m 1 «^- CM CM rh VO vo CI cm CM rh CM rh CM rh CM u /-"s * o CO u n o o rh CM _ A A O O A CO CO o oo m co.$ j- co m co vo o CM CO rh CO 00 CM t c... V^1 rs co >^ vo vo co o m co O CM m CO rh VO ON CM CO ON 00 CO CO is on i i rs -^ CO CI CO -J - >3- rh rh VO VO CO >tf rh r-l rh CM r-l rh rh u U A ON A O A A =_ On y"\ O vo rh m f-^ CO m ON rh CM CI rh p fl id ^ CO CO vo erj co co co «9 O «s/ co co vo m vo co rh m ^ rh CO 1** r*» rh in oo >* r»» 00 ON VO is O co o co ^ CI M CI ^ CI H rh vo vo CI m rh r-l CM CM CM r-l u o o «-*L A A CO CI A O A O o Ts " A fvo A «_ v VO / N A O O CM ON CO ^ CO ON CI rh m on «tf m <f mm CO * s CM CM r-l <t vt CO O VO CO ro r» vo oo <-i in r^ ^ vo r* 00 m CM O NO ON O ^ CO CO CO ^ CI rh rh VO VO CI in on f-l CM CM r-l CM t-^ CM /~\ o 0 JO o -o in A u o o " CM O rh CO 0 ^ " On on on in <t O A O A O H VO> r 03 CO 33 cd ON CO CM CM VO rh CO CM Vt... *» VO ON CO ON >tf CM O vo <*... VO CI ^ <* ON CO O CO J - CO CO CO o on p^ co o m 00 CO P^ in vo CM r-l r-l CM rh ^ CI H ft vo vo CI rh CM o A A A»""\ i o o + o o o vo in A A A o»t tj p>» co <f in co 00 rh VO CM CM CM 00 ci 00 is O 1-^ e... S^ Nlfl Ifl N <? CO ON vo CO rh ON f^. CO rh in 00 *tf r^ 00 on m <3* O ON ON ON <r CO CM CI -^ CO rh rh VO VO in r» CM CM rh rh r-l rh CM A u A o o m AAA CM CM O A O *«r-h y~v O CO rh >tf rh ^ ID H H sj o in <} on O VO H ON s.* vo cm vo r- ^ >J ON vo O CO VO CO CO rh m IS PN VO m cm m CO CM ^ CO O %^ CO CM CO <J- CO rh rh vo vo O vo CM CM CM rh CM A u ^ A AAA O rh A O A A o JL <n to <_ o m ^^ A JD Q ON O >tf O On I*- ON CO CM <t O CI O in IS r-t on... c e sx CM VO 00 CO «J «^ ON VO CM CM VO CO CO r-l m co -i- 00 vo ^ i O to ON ON >3" CO CM CO «J Ci H i-i vo vo CI m CM CM CM rh rh /«-N o o 5* O 05 O J3 n CM A *~^ co A O O A O m ON -Q A A rh CO r-» rh co r-» in vo 00 CI 00 CM 00 CM W ON»... rh r-l CO CM u in... E V_^ CM CO «d- CO <tf >^ on in n ci rn s co h «j 00 r-» cort sj CO CO rh CM O CO <J" CO CM CO -^ CO rh rh VO VO m cm 5-1 CM CM CM rh A «V) «A ^ AAA CO <T js o in O A A A rh O O /'-v O A SCO HCOO O n «} «} m >^ CM rh in 00 rh rh cm vo... CM s. in p» *d» <t vo m co on vo co cm co r** co rh m on ci r^ cm m. ^ 3 CO On «^ On on ^ CO CM CO 4 CI H rh VO VO CI VO CO CO to r-l rh CM rh r-l rh CM r* A A AAA VO CO A TJ A A VO CO VO r- CO rh vo <fr rh r-^ vo r». CM O <t rh CO IS 1 O tt- JO A o CO S CO « CO CM ^w' -^ in CO rh m <f on m ci CO VO CO CO CM *3" 00 <r co ON IS CO 4J CO ON O CM ON O -d CO - CM CO >3" CI rh rh VO vo CO vo O CO r-l CM CM rh CM rh CM E C w s ***» -o nw' Tj "0 sv 0) <u s^> «j vy Cfl \^~ w <l> bq S <u <u c CD u Cfl rh 60 bo 5-i bo CO (U >n ) >^ ^. -N CJ CO 3 CO 5) u rh CM 4-> t-l /-S ^ X-N 5 H ys <0 CM 5 s xs O u 6 E CJ r-n CO- Cfl cm en c y >w V * <o- ^ CO (J u S-i <u >> cu H see Cfl ^-v 5-i E 4J C S~\ 3 1 ) 1 CO ) 5 CO </> CO O H bo bd cm Q) -r-v <*> CO C C c v^ >^ n/ 3 c M X bo O O / \ dp ^v N-' CO H C ih qj 0) ) CO CO C 3 5-i dp ^ o > qj O «H O 5 X lh 0) CO 0) CO H CM rh CO >^ 0) > >- 4J e rh O rh H i-> u e 5h O 3 bo CO UH CO CO >^ rh CO ^J "co rh T3 5-i bo 3 0) ^ x. O to I Cfl TJ bo U U 4-1.o ^~N /-V CU }- H C O O <w O CM \ CO c z1^ to <u H *> r-s dp O 4-1 CO CO H O W CO. (J 4-> CO AJ 4J V) H dp J-i "O >^ 5h ^ dp w O > CO rh «H 5 C C ^-t O J3 <0 J3 CO 0) w i H O w M O CO 4J O CO f z bo C C bo O w C 3 C 43 C 0) O CO 5-i ^ C < -H M >H 0)»H 5-. <U bo *h o T3 U CO U C rh <u u 5-. <B "O bfl rh 4-> 4-> o <u CO co bo cu CO»-i co o x «h <N ; co 5-1 co CO > > CO 0) CO +- -H- 2 it U U < 3 to Q rj h! CA ^ M hj f co c_> <: tx< X tirj Uj > 06 OS 12 W CO 5-1 CO 4-> H CO bo

23 (crcss vlue x no. of lmbs wened) were highest for F, 4/8F nd 7/8F ewes ($320-$298) nd lowest for DLS ewes mted to DLS rms ($ 181). Most of the differences mong genetic groups were sttisticlly significnt. Pure F ewes mted to S rms produced $6.39 worth of retiled lmb for ech kilogrm of their liveweight, $2.75 (76%) more thn pure S ewes. The greter number of lmbs mrketed combined with lower ewe body weight in the present study, nd higher lmb dressing percentge s result of greter ft deposition more thn offset the hevier weights of S lmbs when slughtered t 200 dys. Crosses with high F breeding (4/8F to 7/8F) generted on verge, 39% (32-47%) more revenue per kilogrm of ewe liveweight thn pure S, wheres for crosses with low F breeding (1/8F to 3/8F), the dvntge ws bout 12% (11 to 14%) nd for S x DLS ewes it ws only 3%. The uthor concluded tht crossbred ewes from different combintions between F nd DLS mted to S rms produced lmbs of comprble nd generlly cceptble qulity. In spite of the presence of 50% S ncestry in the lmbs, the tendency for greter ft deposition with incresed proportion of F breeding ws still pprent in the three -breed crossbred lmbs. In report summrizing the different phses of this crossbreeding project Fhmy (1988) concluded tht the dvntge in prolificcy brought bout by using high proportions of F in crossbreeding schemes more thn offsets the slight reduction in crcss vlue of the resulting progeny destined for mrket. At low proportions of F breeding, the overll dvntge over stndrd breed such s the S ws reltively smll Fhmy (1989b) used ovultion records on 214 ewes lproscopied in the fll of 1981 through 1985 together with corresponding lmbing records to determine to wht extent grdul chnge in ovultion level from low to high ffects the repetbility of ovultion rte nd the resulting number of lmbs born. The ewes represented DLS, F nd seven of their crosses rnging from 1/8F to 7/8F. Ovultion rte ws determined by counting the number of corpor lute (CL) present in the ovries 3-5 dys fter mting. The totl number of lmbs born by ewes lproscopied ws recorded. Ov loss in terms of number of ovultions not resulting in lmbs ws lso studied. For ewes which gve no birth following their ltest lproscopy, ll ovultions were considered lost. The results indicted tht the intryer repetbility estimted for ech genetic group rnged from for DLS to 0.93 for 5/8F cross (Tble 8). The interyer repetbility of ovultion rte clculted s product moment correltion ws 0.46 between first nd second, 0.58 between second nd third nd 0.56 between first nd third sesons (vg. 0.53). The interseson intrclss correltion for ech genetic group rnged between for DLS nd 0.54 for 3/8F ewes. Estimtes were lower t both ends of the scle of F breeding in genetic groups nd curviliner reltionship could be fitted to these estimtes s ffected by F breeding. Increse in ovultion rte brought bout increse in vribility. This vribility showed curviliner tendency similr to tht of repetbility. Number of lmbs born incresed linerly (b=0.12**) with incresed proportion 13

24 Tble 8. Lest squres mens nd repetbilities (t) of ovultion rte for DLS, Finnsheep (F) nd their crosses Within- seson ovult ions Between- seson ovultions Genetic group 1st 2nd Men No. ovul. ovul. t No. ovul. t DLS /8F ** /8F /8F * **. 4/8F * * 5/8F ** * 6/8F * /8Ff Avg ** ** f Includes pure Finnsheep. of F breeding. The repetbilities of number of lmbs born were generlly smll nd mostly nonsignificntly different from zero. No definite trend could be estblished. Vribility in number of lmbs born incresed with increse in its level. Tble 8b. Men nd repetbilities for number of lmbs born (LB) nd ov loss (OL) of DLS, Finnsheep (F) nd their crosses LB Mens OL %t Repetbility LB OL DLS /8F /8F /8F /8F /8F /8F /8F All groups ** * 0.14* f 100 ov loss/ovultion rte. The number of ov lost rnged between 0.52 nd 1.35 (Tble 8b). In five genetic groups the percentge of loss reltive to the number of CL counted t lproscopy rnged between 30 nd 35%. The repetbilities of ov loss for the different genetic groups were generlly smll nd nonsignificntly different from zero. The correltions between ovultion rte nd ov loss verged 0.58 wheres those between number of lmbs born nd ov loss verged

25 , The uthor concluded tht repetbility of ovultion rte incresed with incresed ovultion to certin level fter which the reltionship ws less evident. Also tht the dt did not suggest tht repetbility ws strongly ssocited with the vribility within groups of different levels of performnce. Tht lthough both ovultion rte nd number of lmbs born showed similr tendency for liner increse (with increse of F breeding for exmple) trits showed mrked difference in the mgnitude nd tendency of their repetbility estimtes Fhmy, Flipot, Wolynetz nd Comeu (1989) ddressed the question of genotype x diet interction effect on growth rte nd feed efficiency. They exmined the problem t two levels, by using different genetic groups nd sets of twins within ech genetic group. Sets of twin lmbs were ssigned to feeding test from wening until they reched pproximtely 32 kg liveweight. The lmbs were crossbred progeny of five S rms mted to DLS nd F ewes, nd ewes from seven DLS-F crosses rnging from 1/8F to 7/8F. In ddition, pure bred twin lmbs from the S nd DLS breeds were included. One lmb from ech set of twins chosen t rndom received high-energy (HE) diet bsed on concentrte, the other received low- energy (LE) diet bsed on roughges. The HE diet ws mixture of grin, offered free choice nd 250 g of grss silge per lmb dily. The LE diet ws composed of grss silge, offered free choice, supplemented with 20% of the mount of grin consumed by lmbs on the HE diet but not to exceed 250 g per lmb per dy. Tble 9. Lest squres mens nd the rnking of the different genetic groups on high nd low energy diets for verge dily gin nd reltive verge dily gin Averge dily giin Reltive verge s di ly gin High-energy Low- energy High- energy Low- energy No. of Genetic Rnk Mens Rnk Mens Rnk Mens Rnk Mens twin group (g/d) (g/d) (g/d) (g/d) sets S x DLS S x 1/8F S x 2/8F S x 3/8F S x 4/8F S x 5/8F S x 6/8F S x 7/8F S x F DLS x DLS S x S S - Suffolk, F = Finnsheep. The initil weight ws recorded fter n djustment period of 7-21 dys. Lmbs were weighed every 14 dys nd finl weight ws tken when the lmbs 15

26 . reched close to 32 kg liveweight. To ccount for differences mong nimls in initil nd finl weights, reltive growth rte (RADG) ws clculted. The results indicted tht the genotype x diet interction mong genetic groups (breeds) nd between individuls within set of twins (mong nimls) ws not importnt for ADG. The genetic group x diet ws significnt for RADG; the genetic groups which rnked highest nd lowest on the HE diet lso rnked highest nd lowest, respectively, on the LE diet; some of the other genetic groups vried widely in their rnking on the two diets (Tble 9). For the crossbred groups fed LE, RADG ppered to increse with the proportion of F in the nimls; this trend ws not pprent for lmbs fed the HE. Differences in the lest squres mens estimtes for RADG between the HE nd LE fed lmbs rnged from 1.63 g/dy for the S x 5/8F group to 5.54 g/dy for the S x 1/8F genetic group. The combined mong nimls nd twins x diet interction ws not significnt implying tht twin lmbs rnked similrly within ech diet in ADG nd RADG. Genetic group nd feeding tretment significntly ffected feed conversion rtio. The uthors concluded tht the rnkings in growth performnce of one twin lmb on roughge diet nd its twin on concentrte diet do not differ gretly nd tht the procedures pplied in test sttion of feeding lmbs high energy, minly concentrte rtions, re justified for identifying lmb's genetic potentil for growth Fhmy (1990) studied ewe productivity under n ccelerted lmbing system of three lmbings in two yers on 145 ewes representing DLS, F nd seven of their crosses. Ewes were mted in spring (April), utumn (August) nd winter (December) on frm locted t St. Augustin in the Lc St. Jen region. The nimls were born in 1979, 1980 nd 1981 nd were relocted t St. Augustin in 1985 nd Regulr lmbing ewes hd the pportunity to lmb t lest four times. However, on verge ech ewe remined in the herd for 2.6 lmbings. The trits studied were fertility, litter size t birth nd t wening, survivl rte t birth nd litter weight of lmbs born live. The intervl in dys between dte of consecutive lmbings ws clculted nd the corresponding number of lmbings per yer ws obtined. Annul productivity ws clculted by multiplying fertility x litter size t wening x number of litters per yer. The uthor showed tht fertility ws highest in F, 6/8F nd DLS (98, 97 nd 94% respectively, Tble 10). Nerly hlf of the 7/8F ewes filed to conceive. Mortlity t birth ws very low, verging 1.1%. Number of lmbs born live ws 1.19 for DLS nd 2.53 for F. The two most prolific crosses were the 7/8F (2.75) nd 5/8F (2.45). Prewening mortlity ws highest for the 1/8F ewes (17.5%) followed by the pure F (11.2%). The lrgest litters t wening were those of 7/8F followed by 5/8F ewes. The flock verged 1.38 lmbings per yer which corresponded to lmbing ech 264 dys (Tble 10). A high rte of infertility ws responsible for the 7/8F ewes lmbing 1.1 times per yer. The 5/8F nd 6/8F ewes lmbed every 8 months while the other genetic groups hd lmbing intervls between 8.5 nd 9 months 16

27 f Ewe productivity per yer ws highest in the 6/8F group (3.27 lmbs, 55.3 kg) nd lowest in the 7/8F group (1.53 lmbs, 24.6 kg). The pure F ewes produced 3.07 lmbs weighing 43.9 kg per yer compred to 1.71 lmbs weighing 32.1 kg per yer for the DLS ewes. Significnt liner regressions were clculted between number of lmbs born live (b-0.12*), number of lmbs wened (b-0.16**) nd the proportion of F in the cross. Tble 10. Lest squre mens for ewe productivity trits of DLS, Finnsheep (F) nd their crosses Fert- Lmbs Surv- Litter No of Lmbing No. of Ewe Kg of ility born ivl birth lmbs intervl litters prod. lmbs live rte (%) wt wened (d) /yr prod. DLS /8F b b /8F bd cd 1.96 b /8F bd b 1.62 b /8F bd bc 1.93 bc /8F ce cd 2 35 bd /8F be bc 2.21 d /8F " d 2.58 cd F cde bcd bd Avg Ewe productivity - fertility x lmbs wened x No. of litters/yr. f Ewe productivity x verge wening weight. The uthor concluded tht crosses involving different proportions of F breeding conform well to the ccelerted system of three lmbings in two yers without the need of rtificilly synchronizing estrus. Under norml frm conditions, the different combintions produced t higher level thn if subjected to the trditionl system of one lmbing per yer Fhmy (1990b) reported on growth, fertility, prolificcy nd fleece weight of yerlings representing Boorool Merino (B) Romnov (R) nd F first cross nd bckcross with the DLS breed. The yerlings were born in Februry nd Mrch 1987 nd 1988 out of DLS ewes nd DLS, R, F nd B rms (pure DLS nd first crosses) nd DLS ewes nd R x DLS, F x DLS nd B x DLS rms (bckcrosses to DLS). In December, when the ewes were between eight nd nine months of ge, they were distributed eqully into ten mting groups of similr size nd exposed to rms for 6 -week mting period. The sires used were two ech of DLS, R, F, B nd Coopworth. The number of ewes exposed per genetic group per yer ws bout 30. The trits investigted were body weights t birth, 50, 100 nd 365 dys of ge, prewening verge dily gin, fertility, prolificcy, survivl rtes, totl weight of lmbs nd gresy fleece weight t bout months of ge. Romnov nd B first cross nd bckcross lmbs were significntly hevier 17

28 ... t birth thn those of F (Tble 11) while DLS ewe lmbs (3.9 kg) were intermedite. The rnking observed t birth ws the sme up to 100 dys of ge. At one yer of ge R first cross ewes verged 61 kg nd were significntly the heviest group followed by R bckcross (56 kg). At the sme ge R nd F crossbred ewes were significntly hevier thn DLS ewes, which in turn were bout 10% hevier thn the B crosses. Fertility in R crosses verged 96% nd ws bout 13% higher thn in F crosses, which in turn were bout 13% higher thn in B crosses (Tble 11). Almost hlf of the B first cross ewes filed to conceive t 8-9 months of ge compred to bout 25% of the DLS nd only 2.4% of the R first cross ewes. Prolificcy t birth ws highest in R crosses while the F nd B crosses were comprble Litter weight t birth rnged between 5.2 nd 5.5 kg for DLS nd B nd F crosses nd between 19.4 nd 21.3 kg 50 dys lter. Romnov first cross ewes produced litters verging 6.4 kg t birth nd 25.1 kg t wening while for R bck cross the litters verged 5.8 nd 23.1 kg. Gresy fleece weight ws highest in B crosses followed by DLS nd then by R nd F crosses (Tble 11) Tble 11. Lest squres mens for pure DLS, first crosses nd bckcrosses of Romnov (R), Finnsheep (F) nd Boorool (B) with DLS Firsit crosses Bck crosses DLS 1/2B 1/2F 1/2R 1/4B 1/4F 1/4R No. of yerlings Weights in kg t: Birth 3.90bc 3.87bcd 3.69cd 3. 98b 4.06b 3.76d dy 15.7c 15.7c 16.7b 16.7b 17.0b 16.2bc dy 20.2c 20.2bc bc 21.6b dy 50.1c 43. 9d 54.9b c 51.3c 56.4b Reproduction Fertility (2) 7A.5c 50. 7d 88 2b c 78.1bc 93.7 Prolificcy, bi rth 1.36c 1.85b 1.84b c 1.54c 1.79b Prolificcy, 50 dys 1.06c 1.50b 1.41b c 1.25bc 1.53 Litter wt, birth (kg) 5.36b 5.51b 5.35b b 5.19b 5.76b Litter wt, wen ing (kg) 20. Abe 19.6c 21.3bc c 19.4c 23. lb Wool Production Fleece wt (kg) 3.30bc bc 2.98d 3.41b 3.14cd 3. lied The uthor concluded tht R crosses excelled those of B nd F in most of the productivity trits, with the performnce of B nd F crosses being very similr. Boorool crosses excelled in wool production but were mrkedly inferior in fertility t 8-9 months. The productivity of bckcrosses ws inferior to tht of first crosses. Crossbreeding with either types of prolific breeds improved different spects of performnce of DLS sheep. Ech, however, hs reveled some disdvntges Fhmy, Boucher, Poste, Gregoire, Butler nd Comeu (1991) studied growth rte, crcss chrcteristics nd met eting qulity of Finnsheep, Romnov, Coopworth, DLS nd Suffolk breeds together with first nd bckcrosses of Finnsheep, Romnov nd Boorool Merino with DLS. The lmbs were fed from n initil weight of bout 23 kg to slughter weight of 43 kg rtions bsed on 18

29 5 grss silge, brley nd corn supplemented with one of the following protein sources: fishrel (60%), soyben mel (48%) or corn gluten (60%) -blood mel (80%). A fourth rtion with no protein supplementtion served s control. The mounts offered nd refused per ech pen of 11 lmbs (one from ech genetic group) were weighed dily. Weights were tken every two weeks nd the lmbs were slughtered when they reched ner the 43 kg ssigned slughter weight. Routine mesurements on the crcsses were tken nd smple from ech lmb ws evluted for cooking nd eting qulity. The results of the study re presented in Tble 12. Finnsheep lmbs nd crossbred F-DLS lmbs were lighter t birth thn other breeds nd crosses. Pure F lmbs grew slower thn those from the other pure breeds nd were the oldest to rech slughter weight. Finnsheep lmbs hd higher dressing percentge nd higher kidney ft percentge but lower leg percentge s compred to the other pure breeds. Sensory evlution of met smples indicted tht no significnt breed effects were observed, only F met hd more intense lmb flvour thn S met. There were significnt diet effect on verge dily gin, percent kidney ft, percent len, ft nd bone of the 12th rib. Lmbs fed fishmel nd corn glutenblood mel grew fster thn those fed soyben mel nd the control diet. Lmbs receiving protein supplement hd generlly less len nd more ft thn those on the control diet. Tble 12. Lest squre mens for the different genetic groups Pure bre eds First crossesf Bck crosses? Co DLS R F S 1/2R 1/2F 1/2B 1/4R 1/4F 1/4B No. of nimls Birth wt (kg) A Wening wt (kg) Wt t 100 (d) ADG on test Crcss percentges Dressing (Z) Leg (Z) Loin (Z) Shoulder (Z) Kidney ft (Z) th rib mesurements Bckft (mm) Loin-eye re (cm^) Muscle (Z) Ft (Z) Bone (Z) Co Coopworth, R f 1/2 DLS. $ 3/4 DLS. Romnov, F = Finnsheep, B = Boorool Merino. The uthors concluded tht with the exception of ft deposition, F nd F crossed lmbs produced crcsses which were comprble in qulity nd eting chrcteristics to lmbs of other prolific nd met- type breeds. Protein supplementtion hd some effect on growth rte but little effect on crcss nd met qulity. 19

30 4.2 Lvl University, Ste.Foy Studies t Lvl University involved flock of pure Finnsheep nd Suffolk nd crosses between these two breeds. Also semen from Boorool rms ws used to produce Boorool crosses with Finnsheep nd Suffolk Lirette, Seone, Minvielle nd Froehlich (1984) conducted n experiment using 20 cstrte nd 20 entire lmbs slughtered t 120 dys of ge to evlute differences between Finnsheep, Suffolk nd their F x cross in conformtion, clssifiction, tissue distribution, chemicl composition nd orgnoleptic chrcteristics of the crcsses. The results (Tble 13) showed tht verge dily gins of F lmbs were lower thn for other breed groups. Dily weight gins of crossbred lmbs were superior to those of purebred F lmbs nd comprble with those of S lmbs. Dily gins of noncstrted lmbs were comprble with those of cstrted lmbs. Purebred F lmbs hd lighter slughter weights thn lmbs of the other breed groups. In generl, S produced hevier lmbs thn F. Crcss weights of F lmbs were inferior to those of S nd crossbred lmbs. The S breed produced lmbs whose weight, yield nd clssifiction of the crcsses were superior to lmbs from the F breed. Tble 13. Performnce! of cstrte (C) ndl entire (NC) lmbs representing Suffolk (S), Finnsheep (F) nd their crosses Genetic groups Suffo Finnsheep S x F F x S C NC C NC C NC C NC Slughter weight (kg) Averge dily gin (g/d) Dressing (%) Clssifiction Avg. bckft (mm) Kidney ft (%) Shoulder (%) Loin- rck (%) Leg (%) Body muscle (%) Body ft (%) Body bone (%) Wrner -Brtzler (g) Sensory evlution Flvor Juiciness Tenderness f Bsed on five lmbs per breed- sex subclsses 20

31 . Crcss clssifiction of noncstrted F lmbs ws inferior to ll other groups. Posterior limbs nd crcsses of F lmbs were longer thn those of other breed groups. Crossbred lmbs possessed intermedite vlues between the pure breeds for those vribles. Clssifiction ws superior in lmbs hving S s one of the prents. Suffolk intct lmbs presented higher ccumultion of ft t the level of the spinous process lso showed thicker dorsl ft deposits bove the longissimus muscle. On the other hnd, F intct lmbs ccumulted more kidney ft thn S lmbs. Cstrtion hd n influence on the ccumultion of dorsl ft t ll levels mesured. Cstrted lmbs lso ccumulted more kidney ft when expressed s percentge of body weight. Cstrtion nd breed did not influence the reltive proportion of ech cut in the crcss. The longissimus muscle of noncstrted S x F lmbs hd more intense lmb flvor thn tht of cstrted F x S lmbs. Cstrtion produced met with less evident lmb flvor thn tht of noncstrted lmbs. There ws no significnt difference in juiciness between ny of the tretments. Although there were significnt differences in tenderness between tretments, the results were difficult to interpret. The sensory chrcteristics of the met were not relted to the conformtion of the crcsses or of the living niml. The uthors concluded tht F cn be used in crossbreeding for mrket lmbs, becuse no mjor negtive effects were demonstrted on crcss weights, crcss cutbility nd tissue distribution within ech retil cut. Although crcsses from F lmbs received lower clssifiction becuse of conformtion, their crcss tissue distribution, chemicl composition of retil cuts nd orgnoleptic qulity of the met were similr to those of S lmbs. Cstrtion did not influence weight gins or ny other importnt trit to significnt degree Chiquette, Minvielle nd Dufour (1984) conducted study to determine the ssocition between prepubertl plsm LH concentrtion between two nd 10 weeks of ge nd the subsequent ovultion rte nd prolificcy of F, S nd reciprocl crossbred (C) ewe lmbs. The study ws crried out using 17F, 14S nd 26C lmbs. The results indicted tht F nd S lmbs hd significntly higher men plsm LH levels thn C lmbs t six nd eight weeks of ge. However, t 10 weeks of ge the S lmbs hd higher level thn those of F nd C lmbs (Tble 14). When ewes within ech genetic group were clssified ccording to the number of ovultions or litter size, it ws observed tht men LH levels were generlly higher mong more prolific ewes. Number of ewes lmbing s percentge of those bred ws 94, 86 nd 81% for F, S nd C respectively (Tble 14). Finnsheep ewes were the oldest to rech puberty verging 259 dys compred to 234 dys for S with C ewes being intermedite. They reched puberty t 39.5 kg liveweight. Ovultion rte differed significntly between the genetic groups (Tble 14). The F ewe lmbs hd 2.7 ovultions t second estrus fter puberty 1.5 (125%), nd 0.9 (50%) more thn S nd C groups, respectively. Litter size in F ewes ws 73% higher thn in S nd 19% higher thn in C ewes. 21

32 Tble 14. Performnce of Finnsheep (F), Suffolk (S) nd crossbred (C) ewes Genetic groups Fertility (%) Age t puberty (d) b 250 Weight t puberty (kg) Ovultion rte C 1.8 b No. of lmbs born 1.9 l.l c 1.6 b LH concentrtion^ t: 2 wk wk wk b 8 wk b 10 wk b 0.66 f Log of LH concentrtion. The uthors concluded tht using LH concentrtion cross breeds to identify more prolific femles mong prepubertl ewe lmbs might not be fesible since t ny given ge between two nd 10 weeks, ewe lmbs with significntly higher level of LH were not necessrily from the highest ovulting genetic group. However, within breed, LH levels t two nd four weeks of ge between ewe lmbs with potentil for high ovultion rte were consistently but mrginlly higher thn in those with low potentil. The uthors lso showed tht crossing F with S resulted in positive heterosis in ovultion rte nd litter size Cstonguy, Minvielle nd Dufour (1990) crossed Boorool rms with Finnsheep nd Suffolk nd compred the progeny with contemporry Finnsheep nd Suffolk ewes. The trits studied were weights nd gins from birth to 100 dys of ge, weight nd ge t puberty nd different reproductive chrcteristics. The objective of the study ws to evlute the effect of B gene in prolific nd non prolific sheep. The results of the study re summrized in Tble 15. They showed tht S nd its cross were hevier thn F nd its cross t birth nd up to puberty. Finnsheep reched puberty 27 dys erlier thn S nd 22 dys erlier thn B crosses. Ovultion rte, embryonic mortlity nd litter size were highest in B crosses nd lowest in S. Mortlity t birth ws in F nd S but ws 23.7% in B x F cross. The totl kilogrms of lmbs produced vried between 44.9 kg for F to 55.8 kg for B x S, the differences mong the genetic groups being non significnt. The uthors concluded tht the B gene cn increse ovultion rte nd litter size in both prolific nd non prolific sheep. 22

33 , Tble 15. Growth nd reproductive performnce of Finnsheep (F) nd Suffolk (S) ewes nd their crosses with Boorool Merino (B) B x F Genetic B x S groups Number of ewes Birth weight (kg) Wening weight (kg) Weight t 100 dys (kg) Age t puberty (d) Weight t puberty (kg) Ovultion rte Embryonic mortlity (%) Conception rte (%) Gesttion length (d) Litter size t birth Litter weight t birth (kg) Mortlity t birth (%) Litter size t wening Litter weight t wening (kg) Totl kg of lmbs produced C 4.1 b 2.1 c C 23. b 15. C C 33. b b C 47. b C 61. l b 1.7 C b b ^ 142. b 143. b b 1.3 b b b b b 1.8^ ^ 1.3 b 23. b b Cstonguy, Dufour, Minvielle nd Estrd (1990b) studied folliculr dynmic during breeding seson in Boorool x Finn (BF), Boorool x Suffolk (BS) F nd S mture ewes. All ewes were synchronized with sponges impregnted with progestgen. At sponge removl (DO), 14 dys fter insertion, ewes were ssigned to one three groups: Gl) destruction of ll follicles visible on ovrin surfce except the lrgest which ws mrked; G2) destruction of ll visible follicles; G3) mrking of the three lrgest follicles identified. Forty-eight hours fter tretment (D2), folliculr growth ws evluted. At DO, men number of smll follicles (1-3 mm) ws higher (P<0.05) for BS, S nd BF (35.8, 35.1 nd 32.9) thn F (24.9). Lrge follicles (>4 mm) were more numerous in F (3.5) thn in BF, S nd BS (2.6, 2.4 nd 2.1). Dimeter of lrgest follicles ws lrger for S (7.5 mm) thn F, BS nd BF (5.8, 5.1 nd 5.1 mm). In Gl, ewes expressed estrus within four dys fter sponge removl nd ll lrgest follicles mrked t DO ovulted in BF, BS nd S wheres in F ewes two of the six lrgest follicles regressed. In ewes ovulting, only the lrgest follicles ovulted except for one S where one more follicle reched ovultion. In G2, no follicle >4 mm were observed t D2 nd none hd ovulted t estrus following sponge withdrwl. First ovultion occurred for ll ewes bout 16 dys fter tretment nd verged 3.5, 2.0, 1.8 nd 1.8 for BF, BS, F nd S. In G3, proportion of lrgest nd second lrgest follicles ovulting ws higher for S (7/12) compred to BF, F nd BS (3/8, 4/12 nd 2/12). The uthors concluded from these dt tht selection of ovultory follicles occurs in lte folliculr phse in F nd B crossed ewes contrry to S. Smll size follicles pper to induce tresi of lrgest follicle, specilly in prolific ewes. 23

34 5. ONTARIO 5.1 Animl Reserch Centre (ARC), Ottw Finnsheep were used in the development of two Arcott breeds, the Outouis nd Rideu. Mny of the reserch conducted t ARC ws done with pure Suffolk, pure Finnsheep nd the three Arcott breeds under intensive mngement system Wlton nd Robertson (1974) studied the reproductive performnce of smll privte flock of Finnsheep in which ewes were exposed to rms twice yerly in the fll nd in the spring for five consecutive breeding periods. The results indicted tht bout one third of the ewes conceived t ech of the five consecutive exposures nd 72.2% conceived t lest four times during the 2-yer period. In nother group of ewes born one yer lter nd exposed for three times, 71% conceived t ech of the three possible exposures. The men conception- to -conception intervl for ewes excluding those with intervl exceeding eight months ws dys (rnge ). About 43% of ll conceptions occurred within 6 -month period. Assuming gesttion length of 145 dys, lmbing to conception intervl ws clculted t 37 dys or less for 46% of the ewes nd 89% of the ewes hd conceived by 59 dys postprtum. Tble 16 presents percentge of ewes tht conceived nd men litter size for the different sesons. Fll breeding ws consistently more fertile nd prolific. Overll fertility of the F ewes in this study ws clculted t 85% nd verge prolificcy t 1.77 lmbs per ewe exposed. Annul productivity of F under such ccelerted system ws clculted t 3.54 lmbs born per ewe exposed. Tble 16. The percentge conception nd men litter size of Finnsheep ewes exposed to rms on twice -yerly breeding progrm cjeson nd yer of breeding Fll 1968 Fll 1969 Spring 1970 Fll 1970 Spring 1971 Fll 1971 Ewe lmbs bred t 8 months (n-23) (n-14) (n-19) (n-29) Ewe lmbs bred t 12 months (n-8) Ewes more thn 12 months old (n-23) (n=23) (n-34) (n=39) (n=53) 24

35 , Shresth, Peters nd Heney (1982) compred the progeny of Finnsheep Est Friesin (EF), lie de Frnce (IL) nd Suffolk rms mted to different breeds (nd crosses) of ewes. The trits studied were lmb birth, wening, 100- dy nd 140-dy weights. The objective of the study ws to evlute the merit of the four breeds for producing lmbs. The results presented in Tble 17 indicte tht significnt breed-of-sire differences were observed for birth weight with rnking the sire breeds in decresing order s follows: S, IL, EF nd F. Although differences mong the four breeds of sire were not significnt in lmb weight t subsequent ges, severl importnt trends were observed. Importnt, though not significnt, the S surpssed the IL for lmb weight t 140 dys of ge. Suffolk- sired crossbred lmbs tended to be hevier t 140 dys of ge compred to single -cross lmbs sired by the three exotic breeds exmined; however, this difference ws not significnt. Tble 17. Lest squres mens for lmb weights (kg) t birth, wening, 100 dys nd 140 dys of ge ccording to breed of sire No. of Lmb wt in kg t: Source lmbs Birth Wening 100 dys 140 dys Breed of sire within single -cross (EF x SH) + (EF x MM) gb (F x SH) + (F x MM) (IL x SH) + (IL x MM) bc 12. l (S x SH) + (S x MM) C 13. l Breed of sire within bckcross EF (EF x SH) + EF (EF x MM) bc F (F x SH) + F (F x MM) IL (IL x SH) + IL (IF x MM) C 14. l S (S x SH) + S (S x MM) bc l Breed of sire (combined) Est Friesin (EF) Finnsheep (F) b lie de Frnce (IL) bc 13. l Suffolk (S) bc MM - Ottw line. SH - Shropshire. Bckcross lmbs by EF sires were slightly hevier t 100 nd 140 dys of ge compred with Suffolk- sired lmbs from bckcross mtings. Moreover, EF bckcross lmbs were the heviest mong ll crosses t 140 dys of ge. The IL ws similr in crossbred lmb weight to S. Finnsheep crosses from single cross mtings were comprble to Suffolk-sired single-cross lmbs t wening nd t 140 dys of ge. However, bckcross lmbs by F sires were smller t birth, 100 nd 140 dys of ge to S, EF nd IL. 25

36 . Exmintion of the significnt breed-of-sire x breed-of-dm interction for wening weight reveled tht EF rms wened hevier lmbs thn F rms when mted to Ottw synthetic strin ewes, wheres F rms surpssed EF rms when mted to Shropshire ewes In evluting the merit of ech genetic group, the uthors concluded tht, the use of F with known prolificcy long with lmb weights comprble to Sufoik- sired crossbreds indictes suitbility for inclusion into synthetic dm strins. Est Friesin crossbred ewes ppered to hve potentil merit for lmb production. Crossbred progeny of IL, did not demonstrte ny superiority in growth performnce over Suffolk- sired progeny. The S breed showed considerble merit in lmb production comprble to EF, IL nd F. Highly productive ewes from crosses of S nd F pper to hve potentil for improving the efficiency of mrket lmb production Shresth, Fiser, Lngford nd Heney (1983) conducted study to investigte the influence of breed mong other fctors on testiculr mesurements of growing rms. The comprisons were between the three Arcott strins (Cndin, Outouis nd Rideu), Suffolk nd Finnsheep. The trits studied were scrotl circumference, testis length, testis width, scrotl skinfold thickness, nd tonometer score mesured t 6, 8, 10, nd months of ge. Tble 18 showed tht Arcott Cndin nd S rms were the heviest breeds t ll ges followed by the two mternl Arcott lines, Outouis nd Rideu. Finnsheep rms were significntly lighter thn the four other groups. Breed differences observed in scrotum circumference for rms t eight months nd subsequent ges were not significnt t six months. In generl, scrotum circumference of Cndin nd S rms were lrger lthough Outouis nd Rideu were not significntly different from S; F rms hd smller scrotum circumference compred to ll other rms exmined. Testis length for rms t eight nd 10 months vried mong breeds. However, no significnt breed differences were observed for rms t months. Subsequent breed differences for testis length occurred eight months lter. In generl, testis length of Cndin nd S rms were lrger thn those of Outouis nd Rideu, F rms hd the smllest testis length. At months, S rms were similr to Outouis nd Rideu, while F rms were similr to Cndin. Breed did not influence testis width mesurements for rms except t 10 months of ge. Rnking of breeds for testis width tended to be similr to those described for scrotum circumference nd testis length. There were no significnt differences observed mong breeds for scrotl skinfold thickness nd tonometer score. The uthors concluded tht breed differences likely due to susceptibility to chnges in photoperiod suggest tht met type sire breeds such s S nd Cndin hve lrger scrotum circumference, testis length nd body weight compred to those of highly fecund breeds such s F or Outouis nd Rideu. Finnsheep rms hd smller testiculr mesurements compred to ll other rms. However, the significnce of these differences vried s the rm progressed in 26

37 ge. Scrotum circumference ws not greter in the breed with higher fertility in this study, contrry to previous findings. Tble 18. Lest squres mens for body weight nd testiculr mesurements by breed nd ge of rm Age of rm (months) Breed Body weight (kg) Arcott Cndin c 76. l 91. Arcott Outouis b 71. b 88. Arcott Rideu ^ b 86. Suffolk l 74. C 74. b Finnsheep 46. b 54. b d 60. C b Scrotl circumference (cm) Arcott Cndin l Arcott Outouis b 33. b 32. b 36. b Arcott Rideu ^ 33. b 31. l c 36. b Suffolk l bc bc 37.4 b Finnsheep C C bc 34. C Testis length (cm) Arcott Cndin b Arcott Outouis b b b Arcott Rideu b T Suffolk b Finnsheep C 11. C C Testis width ( cm) Arcott Cndin Arcott Outouis b Arcott Rideu b Suffolk Finnsheep C Scrotl iskinfolo! thickness^ Arcott Cndin Arcott Outouis Arcott Rideu Suffolk Finnsheep Tonometir score i (mm) Arcott Cndin Arcott Outouis Arcott Rideu Suffolk Finnsheep ftrns formtion = 100 log 10 (reding in 0.1 mm - 18) 27

38 f Bernon nd Shresth (1984) conducted n experiment to study sexul behvior in sexully experienced rms from three synthetic breeds, Arcott Cndin, Outouis nd Rideu nd two pure breeds (S nd F). The Outouis nd Rideu contined principlly F nd S. Mting ctivity of rms ws mesured during ten minute observtion period. Rms were plced singly in pen nd flehmen, nosing, nudges, pwing, mount ttempts, completed mounts nd time to first mount were recorded. The results showed significnt differences mong breeds for nosings. The F rms hd 40.3% more nosings thn the S nd 25.9% fewer thn the Cndin (Tble 19). Although breed differences were nonsignificnt for other behvior trits, F rms hd 35.1%, 38.3% nd 30.2% more flehmen, mounts nd completed mounts respectively thn the S rms, 43.2%, 62.4% nd 58.7% more thn the Cndin, 54.0%, 51.1% nd 39.7% more thn the Outouis nd 27.0%, 21.8% nd 22.2% more thn the Rideu breed. The uthors concluded tht the high number of completed mounts, nd the lowest time to first mount, when considered with the lower number of other behviour trits indicte tht the F rms re sexully gressive breeders. Tble 19. Mens for incidence of behvior trits by breed Comp- Time to Breed Number pleted first tested Flehmen Nosing Nudge Mount mount mount Pwing Cndin Outouis Rideu Suffolk Finnsheep f Time in minutes include only those nimls tht did mount Shresth, Heney, Fiser nd Lngford (1984) compred the three Arcott breeds of sheep with Finnsheep nd Suffolk in different body mesurements tken t 6, 8, 10, 12, 18 nd 24 months of ge. The mesurements were: hert girth (HG), body length (BL), leg length (LL), metcrpl circumference (MC), withers height (WH) nd hook width (HW). The body mesurements incresed from six to 10 months. The estimtes clculted s percentges of 6 -month vlues were: HG, 12.7; BL, 7.8; LL, 7.8; MC, 6.4; WH, 7.4; nd HW, 5.0 percent. The increses in body mesurements from six to 25 months clculted s percentges of 6-month vlues were: HG, 20.2; BL, 19.2; LL, 8.5; MC, 6.4; WH, 13.0; nd HW, 5.0 percent. The Arcott Cndin rms were lrger in HG thn the S rms, except t eight nd 10 months where no significnt difference ws observed (Tble 20). At months HG of rms from Arcott Cndin ws similr to tht of Arcott Rideu. The F rms hd the smllest HG from six to 13 months of ge, therefter, the F nd S breeds did not differ significntly from one nother. At six months, 28

39 rms of Arcott Outouis nd Rideu were similr to those of the S breed with respect to HG. Lter, t eight months, the S rms were lrger in HG thn those of Arcott Outouis nd Rideu. By 10 months the S rms were lrger in HG thn Arcott Rideu rms only. The HG of the S rms did not differ from those of the Arcott Outouis nd Rideu rms fter 10 months of ge. The HG of the Arcott Outouis nd Rideu rms were similr t ll ges. The Arcott Cndin rms were similr to S rms in BL (Tble 20) except t months when the Arcott Cndin rms were longer. The F rms hd the smllest BL. Only t months the F nd S rms were similr in BL. At six months BL of rms from Arcott Cndin ws longer thn those in Arcott Outouis, wheres, the S rms hd longer BL thn did rms of Arcott Outouis nd Arcott Rideu. At eight months, BL of Arcott Cndin nd S rms ws similr to tht of Arcott Outouis nd Rideu rms This reltionship tended to persist to 25 months. BL of the Arcott Outouis nd Rideu rms were not significntly different from one nother t ny ge. At six months, LL ws shorter in the S rms thn in the Arcott Outouis rms but similr to those of the remining breeds. The F rms hd shorter LL compred to tht of Arcott Outouis nd Rideu. At months of ge, LL of the S nd F rms were similr but significntly shorter thn those of the synthetic dm Arcott Outouis nd Rideu. MC of the S rms ws lrgest t eight nd months. In generl, the S nd Arcott Cndin rms did not differ significntly in MC but were lrger thn those of Arcott Outouis nd Rideu. The F rms lwys hd the smllest MC. Breed differences with respect to WH were observed t 6, 10 nd months of ge. The F rms were similr to S in WH but smller thn the synthetic Arcott lines. At six months, HW of the S rms ws lrger thn tht of the Arcott lines. The F rms hd the smllest HW t ll ges. In generl, the Arcott lines nd S hd similr HW which ws significntly lrger thn tht of the F. In generl, body weights of Arcott lines were similr to S. Finnsheep rms were lighter compred to ll other rms. The body weight of Arcott Cndin, Outouis nd Rideu, S nd F rms t months were 94, 94, 96, 89 n 86 kg, respectively. The uthors concluded tht in generl, the Arcott Cndin rms, synthetic met- type sire breed with lrge proportion of S bckground hd lrger HG thn tht of the S, but ws similr for the remining body mesurements. The F rms hd smller HG, BL, MC nd HW thn did the synthetic breeds nd S rms, but were similr to the S in LL nd WH. The Arcott Outouis nd Rideu rms, developed s synthetic dm strins with 50% F bckground, were similr to one nother in body mesurements. The synthetic dm lines did not differ from the Arcott Cndin nd/or S rms with respect to HG, BL, WH n HW. However, the S rms hd lrger MC nd shorter LL thn rms of Arcott Outouis nd Rideu. 29

40 Tble 20. Lest squres mens for liner body mesurements by breed nd ge of rm Age of rm (months) Breed Hert girth (cm) Arcott Cndin 89. l d Arcott Outouis b 91. l b 96.4 bc b b 101. b Arcott Rideu b b b b b ^ Suffolk b ,8 c b 108. bc 101. bc Finnsheep 81. C C d C 104. C C Body length (cm) Arcott Cndin 71.2 c Arcott Outouis b ^ 84. Arcott Rideu 70. l bc ^ 85. Suffolk bc 85. Finnsheep 65. d b b 78. C b Leg length (cm) Arcott Cndin 32. 3^ ^ Arcott Outouis b l Arcott Rideu bc Suffolk 31.4 c C Finnsheep bc Metcrpl circumference (cm) Arcott Cndin Arcott Outouis 9.2 b 9.5 b 9.7 b 9.7 b 9.8 b 9.7 b Arcott Rideu 9.3 b 9.6 b 10. l b 9.7 b 9.8 b 9.6 b Suffolk C C Finnsheep 7.9 C 8.3 d 8.8 C 9.1 c 8.8 C 8.9 d Withers height (cm) Arcott Cndin 62. l l 72.5 Arcott Outouis ^ 71.4 Arcott Rideu ^ 71.1 Suffolk 61.9^ ^ bc 71.3 Finnsheep 60. b b l c 68.9 Hook width (cm) Arcott Cndin V* Arcott Outouis b l 19. l b Arcott Rideu 18. b b b C Suffolk ^ * Finnsheep 16. d b 17. C Hckett nd Wolynetz (1985) evluted fertility nd prolificcy of Finnsheep nd Suffolk on n ccelerted breeding progrm. Both breeds were contined in ech of two seprte flocks housed indoors yer-round on expnded metl floors in windowless buildings. The two flocks were bred lterntely t 4 -month intervls in Jnury, My nd September. The sheep were exposed to 30

41 either n brupt or constnt lighting regimen. 4-yer period were evluted. Dt from nine breedings during The results showed tht fertility ws significntly higher for ewes mintined in the brupt regimen (66%) thn for ewes mintined in the constnt regimen (46%; Tble 21). Fertility ws significntly lower for ewes bred in September (32%) thn for those bred in Jnury (67%) or My (70%). The 14% fertility observed in the September breedings for nimls mintined in the constnt regimen ws significntly less thn the fertility in the brupt regimen. The lowest fertility in both lighting regimens ws observed in the September breedings. The breed x ewe's previous reproductive performnce nd the rm ge x ewe's previous reproductive performnce interctions were significnt. For ewes previously open, the fertility ws pproximtely 55% for both breeds (Tble 21); however, for the ewes which previously lmbed, fertility of the F (83%) ws significntly lrger thn tht of the S (32%). Tble 21. Fertility nd number of lmbs born to Finnsheep (F) nd Suffolk (S) ewes ccording to breeding seson, light regimen, ge of rm nd previous record Genetic group Light regimen Age of rm Averge Fertility Lmbs born Abrupt Continuous Fertility Lmbs born Fertility Lmbs F S F S < > > (Z) bom Breeding seson Jnury My September Previous record Did not lmb Lmbed Averge The low September fertility ws evident in both breeds (Tble 21) nd the difference in fertility between the two breeds ws smllest in this month. Only in the Jnury breedings ws the fertility of the F (93%) significntly higher thn tht of the S (40%). The prolificcy of the F ewes (2.6) ws significntly greter thn tht of the S ewes (1.6). The difference in prolificcy between the two breeds ws much lrger in the Jnury nd My breedings thn in the September breeding (Tble 21). Overll, the probbility of hving more thn one lmb/ewe lmbing in the F (81%) ws significntly higher thn tht for the S (40%). The uthors concluded tht the difference in fertility between the F nd S breeds is due primrily to the ewes which previously lmbed. It is possible tht mny of the S ewes hd not recuperted from their previous pregnncy. They lso showed tht s expected, the F ewes were more prolific thn the S ewes. The levels of fertility observed in this study demonstrted the fesibility of n 8 -month cycle for breeding sheep mintined indoors yerround with estrous cycle ctivity induced by the lighting regimen. It ppers tht ltering the dylength every four months offers better environment for higher fertility to one service thn does constnt dylength. 31

42 Shresth nd Vesely (1986) evluted dily gin nd body weights of 6356 lmbs from 12 different breeds of sheep from field dt provided by breeders cross Cnd on the Record of Performnce Progrms (ROP) Dt from breeders with two or more breeds of sheep, ech breed being represented by two or more sires of known pedigree were utilized. Performnce vried from one geogrphicl region to nother nd reflected wide vriety of mngement procedures from pstorl systems in Western Cnd to intensive production from housed sheep in Ontrio. Lmbs were weighed between 21 nd 69 dys for 50-dy lmb weight nd between 70 nd 115 dys for 100-dy lmb weight. Significnt differences were observed mong breeds. The rnking of breeds in descending order, reltive to the S for body weight t 50 dys of ge ws s follows: N.C. Cheviot, Hmpshire, Dorset, Oxford, Rmbouillet, Leicester, Corriedle, Finnsheep, Columbi, Southdown nd Lincoln. Corresponding rnkings for body weight t 100 dys of ge were: Oxford, Finnsheep, Hmpshire, N.C. Cheviot, Dorset, Rmbouillet, Corriedle, Leicester, Columbi, Lincoln nd Southdown. Lmbs from the F breed grew s rpidly s those from the Oxford breed. Suffolk lmbs mde the fstest gins between 50 nd 100 dys (339 g) followed by F nd Oxford lmbs (324 g) wheres the slowest gin ws mde by Lincoln (233 g) nd Leicester (242 g) lmbs. Tble 22. Number of lmbs nd lest squres mens nd percent reltive to Suffolk (PRS) for lmb weights t 50 nd 100 dys of ge nd dily gin from 50 to 100 dys Breed of lmb No. of lmbs Lmb weights 50 dys Men PRS in kg t: 100 dys Men PRS Dily gin dys (S) PRS Suffolk Hmpshire Oxford Lincoln Columbi Rmbouillet Dorset Corriedle Leicester N.C. Cheviot Southdown Finnsheep

43 The uthors concluded tht lmbs of the Suffolk breed outrnked ll other breeds nd were followed by the Hmpshire nd Oxford breeds which re lso good met -type breeds nd re recommended for such production. Finnsheep, Dorset, N.C. Cheviot nd Rmbouillet breeds were intermedite nd should be considered for production of lmbs s dm breeds rther thn sire breeds. Corriedle, Leicester, Columbi, Lincoln nd Southdown hd the lowest growth performnce Ainsworth nd Shresth (1987) nlyzed the dt ccumulted for nine yers on Finnsheep, Suffolk, nd three Arcott lines [Cndin, Rideu (40% Finnsheep) nd Outouis (50% Finnsheep)]. The min objective of the work ws to evlute reproductive performnce of ewe lmbs mted t 6.5 to 7.5 months of ge fter tretment with progestogen then injected with PMSG. Since the nimls were bred in Jnury, My or September, it ws lso possible to evlute the effect of seson of mting. The results re summrized in Tble 23 nd indicted tht reproductive performnce ws highest for F, intermedite for Arcott Rideu nd Outouis nd lowest for S nd Arcott Cndin. Body weights showed the opposite tendency, i.e. ws highest in Arcott Cndin nd S nd lowest in F. Ewe performnce trits were significntly ffected by seson of breeding. Fertility nd fecundity were significntly higher for ewes bred in Jnury. The uthors lso clculted regressions of ge nd body weight t mting on fertility nd fecundity. The estimtes were negtive [(-2.26** nd -0.09) nd (-3.83** nd -0.07)] nd only with ge t breeding hving significnt effect. The uthors presented different possibilities to explin the low performnce of the ewes in this study. Tble 23. Lest squre mens for reproductive trits by genetic group nd breeding seson No. of ewes Age t Body weight Fertility Fecundity exposed breeding t breeding (%) (%) (kg) (d) Genetic group Finnsheep 200 oiqb d 61. C 109. C Suffolk c 48. l c l Cndin Outouis l b 52. b 87. b Rideu b 47.0 C b 89. Breeding seson Jnury My b 64. b September b 60. b Ivn (1988) used 40 crossbred Finnsheep x Shropshire x Suffolk rms s n niml model to study the effect of funtion on ruminl solubility nd liver content of copper in sheep fed low nd high copper diets. 33

44 Shresth nd Heney (1990) nlyzed records on 7083 ewes representing Arcott Cndin, Outouis nd Rideu, Suffolk nd Finnsheep to evlute gesttion length, prolificcy, multiple birth, body weight nd totl birth weight. The ewes divided into two flocks were mted in Jnury, My nd September under n 8-month breeding cycle. The results presented in Tble 24 indicted tht Arcott Cndin nd S ewes (met type) hd gesttion lengths of 147 nd 146 dys, respectively, compred to 145 dys for Arcott Outouis nd Rideu ewes nd 144 dys for F ewes (prolific types). In ll five breeds, there ws progressive reduction in gesttion length with increse in litter size from one to five lmbs The F ewes were the most prolific in this study. The frequency of multiple birth ws similr mong Outouis, Rideu nd F ewes nd pproximtely 20% greter thn Cndin nd S ewes. At breeding, S ewes were 5.6 kg hevier followed by Cndin ewes, then by Outouis nd Rideu ewes which weighed less thn Cndin ewes t breeding by 8.3 nd 6.3 kg, respectively. Finnsheep ewes were significntly lighter t breeding thn other ewes in this study. Totl birth weight of lmbs rnked by breed ws s follows: Rideu, Cndin, Outouis, S nd F. Finnsheep lmbs were 2 to 2.5 kg lighter in totl birth weight thn the other breeds. Tble 24. Lest squres mens for gesttion length, prolificcy, multiple birth, body weight t breeding nd totl birth weight by breed Trit Breed Cndin Outouis Rideu Suffolk Finnsheep Prolificcy b 2.4 C d Multiple birth (%) b b l b Body wt t breeding (kg) b C d 60. e Totl birth wt (kg) g 4 bc 8.2 b 8.5 C 8.0 b 6.2 d Gesttion length (d) Avg. ll nimls b b C d Single Twin b 145. b 145. l b b b 144. C C Triplet l c C C C Qudruplet d d d Quintuplet e d 142. ~ d 142. Totl number of ewes lmbing for the Cndin Arcott, Outouis Arcott, Rideu Arcott, Suffolk nd Finnsheep breeds were 1530, 2368, 2421, 211 nd 553, respectively. 34

45 6.1. University of Mnitob, Winnipeg 6. MANITOBA Snford, Plmer nd Howlnd (1977) studied the chnges in profiles of serum luteinizing hormone (LH), follicle stimulting hormone (FSH), testosterone, in mting performnce nd ejculte volume in Finnsheep nd Mngr Synthetic (Line-M) rms during the ovine breeding seson. In erly August, mid- September, erly November nd mid- December four rms of ech breed were bled t 20 -minute intervls for two 8 -hour periods. Rms were bled while in the bsence then presence of ewes in estrdiol -induced estrus. An ejculte ws lso collected from either five or six of the rms during these months. The results showed tht certin of the endocrine chrcteristics investigted were found to differ with breed (Tble 25). Concentrtions of FSH nd the height of the testosterone peks were consistently greter in F thn in Line-M rms. Other chrcteristics such s men levels of LH nd testosterone nd LH-pek height ppered to vry between breeds during only certin months of this study. Mting performnces of F nd Line-M rms were comprble during the months of this study. Episodic increses in serum levels of LH nd testosterone were evident in ll rms during ech 8 -hour period, while FSH fluctuted very little from bseline concentrtions. Progressive chnges in the profiles of serum LH nd testosterone occurred in rms of both breeds s the breeding seson dvnced. Peks in LH becme more frequent nd decresed in height, nd the number nd height of the testosterone peks incresed. Serum FSH concentrtions were highest in September. Tble 25. Serum hormone concentrtion in Finnsheep (F) nd Mngr synthetic (LM) rms during the breeding seson in bsence or presence of ewes in estrus In bsence of ewes In presence of ewes in estrus in estrus Aug. Sept. Nov. Dec. Aug. Sept. Nov. Dec. Men LH level F (ng/ml) LM Men FSH level F (ng/ml) LM Men testoterone F level (ng/ml) LM Mting ctivity ws ssocited with increses in the frequency of LH nd testosterone peks in August nd September. The number of mtings per eight hour nd ejculte volume incresed between erly August nd erly November; both were highest in November when the level of serum testosterone ws mximl. Monthly chnges in testosterone concentrtion in seminl plsm were moderte compred with those in serum. 35

46 6.1.2 Snford, Beton, Howlnd nd Plmer (1978) used four 11 month- old Finnsheep rms s model to determine the fesibility of producing two reproductive-endocrine cycles in the rm in one-yer period. This ws chieved by exposing rms to consecutive 6 -month "nnul" photoperiod cycles. The intent of the study ws to compre the sequence nd timing of the chnges in luteinizing hormone (LH), follicle stimulting hormone (FSH), prolctin (PRL) nd testosterone secretion in rms exposed to the controlled photoperiod regime with those tht occur in rms exposed to nturl photoperiod vritions. Two of the rms were put in "light-proof" room with ewes, while the remining two nimls were put with other rms in pen locted in n open- front brn. Rms in the "light-proof" room were exposed to three consecutive 6 -month "nnul" photoperiod cycles between 31 December nd 21 June. During the first cycle, dylength ws shortened from 17.5 to 13.5 hours nd then lengthened to 17.5 hours t the rte of 15 minutes every 5th or 6th dy. Dylength rnged from 17.5 to 8.0 hours nd ws chnged t the rte of 15 minutes every 2nd or 3rd dy during cycles two nd three. From mid- June nd for 12 months, ll rms were bled on 12 occsions spced 3-5 weeks prt. Smples were ssyed to ssess chnges in LH- nd testosterone-pek frequencies nd heights. Serum PRL concentrtion ws determined by rdioimmunossy. The results showed tht rms exposed to nturl photoperiod exhibited increses in serum LH, FSH nd testosterone concentrtions nd decline in PRL concentrtion during the first three months (21 June-21 September) of diminishing dylength. Two distinct endocrine cycles per yer were produced in rms exposed to 6 -month "nnul" photoperiod cycles. Periods of diminishing dylength were ssocited with incresed in serum FSH nd testosterone concentrtions nd decrese in serum PRL concentrtion; these trends were reversed during periods of incresing dylength. The uthors concluded tht in generl the reproductive -endocrine chnges tht normlly occur in the rm during 12 -month period cn be reproduced in the sme sequence in 6 -month period by photoperiodic mnipultion Kennedy nd Belluk (1987) conducted study to evlute the effect of continuously dministered moderte doses of -gonist clonidine on growth, feed efficiency nd body composition of Suffolk nd Finnsheep crossed popultion consisting of pproximtely 50% Finnsheep blood. The nimls were divided into three groups, nimls of the first group served s control, in the second group nimls were implnted t dys 1, 29 nd 57 of the experiment, with mounts rnging between 4.7 nd 8.0 /xg clonidine -HC1 per kilogrm liveweight per dy. Animls of the third group were implnted, on the sme dys, five times the mounts of clonidine dministered in the second group. The results summrized in Tble 26 showed tht the F cross consumed more feed nd grew fster thn S, but feed efficiency ws similr in both genetic groups. Significnt differences between the two genetic groups were observed in kidney ft percent nd re of longissimus dorsi of 10-12th ribs. 36

47 Tble 26. Growth, feed efficiency nd body composition of Suffolk (S) nd Finnsheep (F) crossed FC lmbs in control (C) nd clonidinedministered groups (D nd 5D) Breed Mens Suffolk 5D Finnsheep cross C D 5D FC ADG (kg) ,, Feed intke (kg) , ,, Feed efficiency , Slughter weight (kg) , , Dressing (%) , , Kidney ft (%) , C D 5D 10-12th ribs Len (%) Bone (%) Ft (%) Longissimus dorsi re (cm 2 ) Wter (%) Protein (%) Ft (%) The effect of clonidine implnttion ws significnt on dressing percentge, kidney ft nd ft composition of the longissimus dorsi. The interctions genetic group x tretments nd genetic group x tretment x phse of implnttion were significnt on ADG. The uthors concluded from the study tht continuous dministrtion of clonidine to growing rm lmbs ws found to depress kidney ft percentge in dose relted mnner with the effect more pronounced in F-crossed lmbs. The effects of low nd high doses of clonidine were positive in S lmbs nd negtive in F-crossed lmbs. 37

48 7. SASKATCHEWAN 7.1 University of Ssktchewn, Ssktoon Jeffcote, Rwlings nd Howell (1984) exmined the durtion of the breeding seson in five breeds or crosses of which two were Finnsheep crosses. The uthors lso studied fertility nd endocrine responses of these genetic groups to estrus synchroniztion with or without PMSG dministrtion during the breeding seson. In ddition the responses of ewes induced to breed out of seson, with or without pho toper iod mnipultion scheme designed to stimulte reproductive ctivity, were evluted. The genotypes studied were Rmbouillet (RL), Columbi (C), Suffolk, RL x Finnsheep (RLF) nd C x Finnsheep (CF). The RL, C nd S ewes were mted to F rms while the RLF n CF ewes were mted to Hmpshire or S rms. In yer 1, 22 ewes from ech genetic group were treted with intrvginl sponges, hlf of these ewes received 500 IU PMSG. Ewes were plced with vsectomized rms nd were tested for signs of stnding estrus. Blood smples were obtined regulrly from ll ewes. In yer 2, ll synchronized ewes were injected with 500 IU PMSG nd plced with rms for 40 dys. While some ewes from ech genetic group were exposed to mbient dylight up to the time of breeding, the remining ewes were exposed to n rtificil photoperiod designed to induce reproductive cyclicity. The results showed tht the breeding seson ws longest in the F crossbred ewes nd shortest for the S ewes (Tble 27). During the breeding seson (October), 95% of ll ewes treted with progestin sponges showed estrus following sponge removl. Administrtion of PMSG did not influence estrus response. Out of seson (My), 93% of treted ewes showed estrus. All of the ewes treted in My received PMSG nd photoperiod mnipultion did not influence the number of ewes in estrus following sponge removl. During the breeding seson, 16% of ewes bred by fertile rms were rebred t the estrus subsequent to the synchronized estrus. Out of seson, none of the ewes under norml lighting were rebred, but 20% of the photoperiod-mnipulted ewes were rebred. During the breeding seson 50 ewes housed with vsectomized rms gve n verge time from sponge removl to estrus of 43.1 ± 1.8 hour. Time to estrus ws significntly ffected by PMSG tretment (PMSG- treted ewes 39.4 ± 1.8 hours, controls 48.0 ± 3.1 hours). The overll gesttion length for ewes bred in My ws significntly shorter thn for ewes bred in October (Tble 27). This difference ws pprent within breeds. Rmbouillet ewes hd longer gesttions thn S or crossbred ewes. In fll -bred ewes (October) PMSG did not influence the numbers of C nd S ewes lmbing. In spring-bred ewes (My) photoperiod mnipultion improved the numbers of ewes lmbing, but not the numbers of crossbred ewes lmbing. Prolificcy ws not consistently ffected by PMSG tretment or seson, but the crossbred ewes produced more lmbs (Tble 27). None of the endocrine prmeters studied were ffected by breed of ewe. The uthors concluded tht the extended breeding seson of RLF nd CF ewes would fcilitte the use of controlled breeding, tht PMSG tretment did not ffect fertility following fll breeding nd tht fewer purebred ewes lmbed following spring breeding under nturl dy light. 38

49 C.. Tble 27. Reproductive performnce of ewes of five genetic groups under different mngement procedures First Estrus Ls t Breed seson (d) Gesttion Fertility (Z) Proli ficcy len/tth (d) Oct. Oct. My My Oct. Oct. My My Fll Summer No PMSG PMSG PMSG PMSG No PMSG PMSG PMSG PMSG mting mting Nturl dy light Photo Nturl dy light Photo RL Aug. 7 Mr C Aug. 18 Mr S Aug. 19 Feb. 2 < RLF Aug. 7 Apr RLC Aug. 11 Apr RL Rmbouillet, = Columbi, S = Suffolk, F Finnsheep Rwlings, Jeffcote nd Howell (1987) conducted study to exmine the performnce of Suffolk, Columbi nd Rmbouillet ewes nd their Finnsheep hlfcrosses in n intensified production scheme. The 288 ewes vilble were split into three groups; ech contined 16 ewes of ech of the three purebred nd three crossbred ewe types. Group 1 served s control, nd ewes were bred nturlly ech October. Groups 2 nd 3 were intensively mnged, ewes in these two groups were bred every eight months, with the two groups lmbing four months out of phse with ech other. The breedings occurred in Jnury, My nd September. Over the 3 -yer study period, group 2 ewes lmbed five times nd group 3 ewes four times. Purebred ewes were plced with F rms, 50% of the crossbred ewes were plced with S rms nd 50% with Hmpshire rms Intensively mnged ewes were bred t estrus synchronized by 12-dy tretment with intrvginl sponges. Ech ewe received 500 IU PMSG. Rms were left with the ewes for 25 dys. Ewes to be bred in My were subjected to 18 hours of light per dy throughout the preceding Jnury. This ws followed by reduction in dylength to eight hours of light per dy t breeding. Mens for the number of ewes lmbing of those put to the rm (fertility), prolificcy nd lmb losses to wening were clculted for ech cycle. Dt for mngement system nd breed were combined to exmine differences between purebred nd crossbred ewes. To compre lmb production of the two mngement systems, the number of lmbs born per yer ws clculted nd compred. The number of ewes lmbing of those put to the rm ws higher in extensively mnged ewes thn for the intensively mnged nimls (Tble 28). Finn-cross ewes hd higher prolificcy (216 ± 10%) thn purebred ewes (165 ± 8%). There ws significnt interction between breed nd mngement system. The seson in which ewes were bred ffected both fertility nd prolificcy. Breedings in October nd Jnury resulted in the highest numbers of ewes lmbing while My breeding resulted in the lowest fertility. Annul lmb production ws incresed by intensified mngement nd differed mong breeds. Overll, the crossbred ewes produced more lmbs per yer thn the purebreds (231 vs 166) 39

50 . Tble 28. Fertility, prolificcy nd nnul lmb production of Rmbouillet (RL), Suffolk (S) nd Columbi (C) breeds nd their crosses with Finnsheep (F) under intensive nd trditionl mngements. Genet ic groups Trit Mngement RL S C FRL FS FC Overll Fertility (%) Intensive Trditionl Prolificcy Intensive Trditionl Annul lmb Intensive production Trditionl Lmb losses from birth to wening were lower for lmbs produced by purebred ewes (11%) compred with crossbred ewes (15%). Annul ewe replcement rte ws 17% for the control flock nd 25% for intensively mnged ewes. The incidence of culling for infertility ws greter in intensively mnged ewes (15%) thn in the controls (4%) The uthors concluded tht the intensive mngement scheme incresed ewe productivity. However, lmb output in most of the breed groups ws not incresed by the expected 50%. This discrepncy lrgely reflects the reduced fertility of ewes when bred out of seson in My. They dded tht intensifiction did not produce higher lmb losses, but lmb losses from the more prolific F- cross ewes tended to be higher. F x C ewe would pper to offer the highest potentil productivity under this intensive mngement regimen Rwlings (1987) used Finnsheep -Rmbouillet crossbred ewes to determine if criticl dy length, simple contrsts in dy length, or photosensitive phse were importnt in reducing reproductive sesonlity in the ewe. Strting in the fll when nturl dy length ws 8.5 hours, the nimls were divided into three groups. The groups were subjected to different ptterns consisting of cycles of short to long to short dys pplied over periods of six months. The increse or decrese in dy length were either grdul over periods of three months or brupt, followed by constnt dy length for three months. In the cycles pplied, the length of both the longest nd shortest dy ws vried, s ws the length of time to which the ewes were exposed to the chnge. The occurrence of periods of reproductive cyclicity ws determined by mesuring progesterone concentrtion in serum collected on Tuesdys nd Fridys of ech week. The results indicted tht incresing dy length from short dys to hours, 17.5 hours, or 22 hours, resulted in ewes entering nestrus within 110, 108 or 96 dys respectively, of the first dy of the period of incresing dy length. When dy length ws incresed to 14 hours the response time for four 40

51 ., ewes ws 128 dys, but further four ewes did not enter nestrus until the following dy length cycle (n increse in dy length to 17.5 hours). None of the response times bove differed significntly. An brupt decrese in dy length resulted in more rpid return to reproductive cyclicity thn grdul decrese. In ddition, there ppered to be n inverse reltionship between the length of the longest dy of tretment cycle nd the length of time tken for ewes to return to reproductive cyclicity, following subsequent nd brupt decrese in dy length. When dy length ws bruptly reduced fron 22 hours to 16.5 hours no ewes cycled within 140 dys. When dy length ws bruptly reduced from hours to 15 hours hours, or 7.5 hours, ll ewes resumed reproductive cyclicity. Introduction of one hour of drkness from the 12th hour fter dwn, into 17.5 hours dy, resulted in the resumption of reproductive cyclicity with response time similr to reduction in dy length from 17.5 hours to hours or 7.5 hours. However, the vribility in response time ws quite lrge. The influence of the length of time of exposure to long dys on the subsequent response of ewes to reduction in dy length indicted tht when dy length ws grdully incresed to 17.5 hours, ddition of further one month of 17.5 hours dy did not ffect the time tken for ewes to resume reproductive cyclicity, following subsequent reduction in dy length (95 dys). However, when dy length ws grdully incresed to 22 hours, then bruptly reduced to nd held t 17.5 hours for 4.33 months, subsequent reduction to 7.5 hours resulted in rpid resumption of reproduction cyclicity (55 dys). In ddition, extending the time ewes were exposed to long dys (17.5 hours) resulted in miniml response time following reduction of dy length to 15 hours The uthor concluded tht there is circdin rhythm in photosensitivity in the ewe. In ddition, the sensitivity of the photosensitive phse my undergo sesonl fluctutions. The dy length cycles used would probbly hve msked long term refrctoriness to incresing or decresing dy lengths. This hs been suggested s n importnt component of the mechnisms leding to the cesstion nd onset of reproductive cyclicity in the ewe. However, dt from this study suggested tht more positive mechnism initites nestrus, t lest in the breed of ewe used in this study. 41

52 8.1 Reserch Sttion, Lethbridge 8. ALBERTA Vesely (1978) nlyzed records of 1556 lmbs ccumulted over 3-yer period from mting Finnsheep nd Dorset rms to purebred nd crossbred ewes. The objectives were to evlute wening weights, weights per dy of ge to mrket nd crcss grdes of lmbs fed to weight rnge between 43 nd 50 kg. The results of the study re summrized in Tble 29 nd showed tht verge wening weight of Dorset sired lmbs verged 26.8 vs 25.9 kg for 1/2 F, the difference being significnt. Weight per dy of ge to mrket ws similr for both sired breeds (236 g) Averge crcss score of F-sired lmbs ws slightly,. though significntly, better thn tht of Dorset-sired lmbs. The uthors concluded tht both Dorset Horn nd F rms produced crossbred lmbs with stisfctory growth nd crcss merit. Tble 29. Weight t wening nd crcss grde of lmbs sired by Finnsheep (F) nd Dorset (D) rms Breed of sire Breed of dm No. Wening weight (kg) Weight/ dy of ge (g) Crcss grde D F x x Pure breeds Pure breeds D F x x 2 2 breed crosses breed crosses D F x x 3 3 breed crosses breed crosses D F x x 4 4 breed crosses breed crosses D F Mukhoty nd Peters (1982) studied the influence of genetic group nd sex on muscle weight distribution of 60 rm nd ewe lmbs representing crosses of Finnsheep or Ottw MM strin with British breeds. The lmbs were slughtered between 37 nd 48 kg liveweight, verging 42 to 43 kg in ech genetic groupsex subclss. Physicl seprtions were mde of eight joints from the left side of ech crcss into muscle, bone nd ft. Muscle weight distribution ws then studied by three methods: expressing joint muscle s percentge of totl side muscle; linerly djusting men weight of muscle in ech joint with totl muscle held constnt; nd considering ll joint muscle weights simultneously, utilizing discriminnt function technique. The results indicted significnt genetic group differences only in the bdominl muscles. Sex exerted strong 42

53 , influence in the muscles of the bdominl nd neck regions. interction ws significnt in the bdominl region. Genetic group x sex Vesely nd Swierstr (1985) compred prolificcy, lmb mortlity, kilogrms of lmbs wened nd mrketed per ewe exposed nd rte of ttrition over period of 4.5 yers of Dorset Horn- nd Finnsheep-sired ewes under different breeding systems (trditionl vs ccelerted) nd light control (nturl vs controlled conditions). A group of ewes mintined under synthetic light regimen (LT, 4 months long dys - 16 hours light, 4 months short dys - 8 hours light) nd exposed to rms every eight months in Jnury, September nd My, ws compred with two similr groups under nturl light conditions, one group ws exposed to rms once yer in the fll (CI) nd the other every eight months (C2). Prolificcies of crossbred F were higher thn those of crossbred Dorset. On verge, crossbred F ewes produced bout 250 lmbs compred to 180 lmbs/100 ewes lmbing for Dorset cross. Lmb mortlity of crossbred F ewes ws bout 31% compred to 14% for Dorset crossed ewes (Tble 30) Tble 30. Lest- squres mens for verge lmb production per ewe over period of 4.5 yers from estblished flocks of 69 ewes (control I) in five lmb crops nd 67 ewes (control 2) nd 64 ewes (light tretment) in seven lmb crops Fctor No. of lmbs Pre -weni n S Kg of lmbs Attritiion (%) Born Wened mortlity (%) Wened Mrketed F D Cross of ewe Hlf-Dorset Hlf- Finn 8.9 b Mngement Control Control Light tret b b b F == Finnsheep D - Dorset. The dvntge of crossbred F ewes in lmb production due to higher prolificcies prcticlly disppered when compring kilogrms of lmb wened or mrketed/ewe exposed to rm. In the CI group, the mount of lmb wened or mrketed/crossbred F ewe exposed ws similr to, or less thn, tht from crossbred Dorset ewes in ll cycles. In C2 nd LT groups, crossbred F ewes exceeded crossbred Dorset ewes in only two of seven cycles in terms of kilogrms of lmb mrketed/ewe exposed to rms. During the two out-of-seson breedings (cycles 3 nd 6), LT ewes produced 76 kg more lmb t mrket thn did C2 ewes. However, C2 ewes were more productive in cycles 1 nd 2. 43

54 ., The overll ssessment of the two genetic types of ewes nd the three mngement systems (CI, C2 nd LT) is presented in Tble 30. It summrizes production trits ccumulted over the durtion of the experiment. This nlysis took into considertion lso the rte of ttrition of ewes during the course of the experiment. When ll fctors were combined, the higher production potentil of crossbred F ewes ws eliminted. These ewes produced 1.5 more lmbs over the 4.5-yer period but rised equl numbers of lmbs to wening. Overll they produced bout 14 kg less lmb mrketed. This difference ws not significnt. The loss in dvntge of the crossbred F ewes ws lso due, in prt, to higher ttrition of these ewes in ll three mngement systems. Differences in ttrition between the two genetic groups of ewes were significnt in C2 nd LT. However, these results my be misleding s fr s lifetime production is concerned, becuse higher ttrition of the F ewes occurred only during the lst stges of the experiment s result of cumultive effect of mngement. No doubt ewes bering 2.5 lmbs/conception every eight months require different level of mngement throughout their life nd such ws not the cse. The uthors concluded tht ewes exposed to rms every eight months without ny gents inducing estrus did not conceive in stisfctory numbers. Crossbred ewes with 50% Dorset Horn blood did not exhibit higher conception rtes in the spring thn crossbred ewes with 50% F blood. Light control s pplied in this experiment ws relible gent for induction of estrus, but ewe nd lmb mngement procedures must be optimized in order to cpitlize on dditionl lmbs Vesely nd Swierstr (1986 nd 1987) showed tht production systems bsed on breeding ewes t 8 -month intervls produce lmbs tht re born in prcticlly every seson of the yer. They conducted study to evlute reproductive trits of ewe lmbs representing eight genetic types born in winter, spring, summer nd fll. Eight genetic types of ewe lmbs [Dorset x 3/4 Dorset (DD) Dorset x 3/4 F (DF), F x 3/4 Dorset (FD), F x 3/4 F (FF), Romnov x 3/4 Dorset (RD), R x 3/4 F (RF), R x Western (RW) nd Western x Western (WW) ] born in Februry, Mrch nd October nd Mrch nd June of the following yer were evluted for conception rte, ovultion rte, litter size, prentl mortlity nd weight nd ge t conception. Vrition mong the Dorset, F nd R sires ws found to be significnt on conception (rte nd ge), ovultion rte nd litter size (Tble 31). Romnov, n erly-mturing breed, reduced significntly the ge t conception s compred with the ewe lmbs sired by D or F rms; ewe lmbs sired by F rms hd significntly higher ovultion rte nd litter size thn the ewe lmbs sired by D rms. Ewe lmbs sired by R rms hd significntly higher ovultion rte nd litter size thn the ewe lmbs sired by F rms. Dm effect ws found to be significnt between the 3/4 D nd 3/4 F ewes. Three-qurter F dms rised ewe lmbs tht mtured erlier, were lighter nd more prolific thn those rised by 3/4 D dms. Genetic dditive effects in ovultion rte nd litter size trits re the most powerful chrcteristics of the F nd R breeds. The results demonstrted tht the R my be slightly more prolific thn the F. 44

55 86 5 The youngest lmbs t conception were the R crosses, prticulrly the RD nd RF. The heviest ewe lmbs t conception were lwys those of Western bckground. The lightest were most often the F crosses (FF nd RF). Crosses differed s to ovultion rte, with the FF nd RF generlly hving the highest, nd WW nd DD the lowest. Month of birth of the ewe lmbs significntly ffected their reproductive performnce. Only five of the 57 ewe lmbs born in October showed sexul ctivity in lte winter nd erly spring. Most of the vrious crosses hd conception rtes of >90%. The uthors concluded tht dditive genetic effects in ovultion rte nd litter size of the R re similr to tht of the F. Romnov crosses (RF, RD, RW) conceived t the lowest ge (226, 227, 231 dys). Ewe lmbs of ll genetic types, with the exception of the Western ewe lmbs, hd similr reproductive rtes if born in Februry, Mrch or June. Lmbs born in October conceived not in their yer of birth but in the following yer, when they were bout 11 months old. Tble 31. Lest squres mens of conception rte, ge nd weight t conception, ovultion rte, prentl mortlity nd litter size for sire, dm nd cross Effect At concep tion Prentl Litter Age Weight Ovultion mortlity size (kg) (d) Dorset Horn Sire Finnsheep (F) Romnov (R) (D) Dm 3/4 Dorset Horn (D) 3/4 Finnsheep (F) c b b 231 b b b b b Cross DD DF FD FF RD RF RW WW 251 b b 1.48 cd bc 234 b b 1.83 bcd bc 247 b 49. l b bc bc 242 b 45. b b b 227 b b 2.28 bc bc 226 b 44. b b b 2 2 gbc b d c W - Western type ewes McClellnd (1989) studied wool qulity of ewe lmbs nine to 11 months of ge sired by Finnsheep, Romnov, Dorset nd Western Rnge rms. The trits studied were stple length, men fibre dimeter, clen scored yield, presence of medullted fibres nd qulity number. The results re summrized in Tble 32. Ewes sired by F nd R sires were significntly discriminted ginst by Cndin clssers. 45

56 Tble 32. Wool chrcteristics of purebred nd crossbred ewe lmbs 9-11 months of ge Breed of sire Dorset Finnsheep Romnov Western (D) x (F) x (R) x (W) x Breed of dm 3/4D 3/4F 3/4D 3/4F 3/4D 3/4F W W Stple length (mm) 81 Men fibre dimeter (/0 30 Clen scored yield (%) 65 Medulltion (%) Lmbs with 7/8F blood (F x 3/4F) hd the longest stple nd third finest fleeces. None of the ewes sired by F, D or W rms hd medullted fibres present in the fleece wheres R x 3/4F cross hd 50% medullted fibres. Color fibres were present in three of the 36 R x 3/4F ewes. 46

57 9. REFERENCES Ainsworth, L. ; Shresth, J.N.B The reproductive performnce of ewe lmbs in controlled environment. Anim. Prod. 44: Bernon, D.E.; Shresth, J.N.B Sexul ctivity ptterns in rms. Cn. J. Comp. Med. 48: Cstonguy, F. ; Minvielle, F. ; Dufour, J.J Reproductive performnce of Boorool x Finnish Lndrce nd Boorool x Suffolk ewe lmbs, heterozygous for the F gene, nd growth trits of their three-wy cross lmbs. Cn. J. Anim. Sci. 70: Cstonguy, F. ; Dufour, J.J.; Minvielle, F. ; Estrd, R. 1990b. Folliculr dynmics in Boorool x Finnish Lndrce nd Boorool x Suffolk ewes heterozygous for the F gene. J. Reprod. Fertil. 89: Chiquette, J.; Minvielle, F. ; Dufour, J.J Prepubertl plsm LH concentrtion, ovultion rte nd prolificcy in Finn, Suffolk nd Finn- Suffolk ewes. Cn. J. Anim. Sci. 64: Fhmy, M.H Body nd crcss mesurements of DLS nd Finn sheep x DLS lmbs slughtered t three light body weights. World Rev. Anim. Prod. 15: Fhmy, M.H Mternl performnce of DLS sheep nd its crosses with the Finn Lndrce breed. Proc. World Conf. Anim. Prod., Tokyo, Jpn 2: Fhmy, M.H The ccumultive effect of Finnsheep breeding in crossbreeding schemes: Growth nd crcss trits. Cn. J. Anim. Sci. 65: Fhmy, M.H The ccumultive effect of Finnsheep breeding in crossbreeding schemes: Wool production nd fleece chrcteristics. Cn. J. Anim. Sci. 67:1-11. Fhmy, M.H The ccumultive effect of Finnsheep breeding in crossbreeding schemes. J. Agric. Sci. Finl. 60: Fhmy, M.H The ccumultive effect of Finnsheep breeding in crossbreeding schemes: Mrket lmb production from crossbred ewes. Cn. J. Anim. Sci. 69: Fhmy, M.H. 1989b. Repetbility of ovultion rte number of lmbs born nd ov loss in sheep with different ovultion rtes. Cn. J. Anim. Sci. 69: Fhmy, M.H The ccumultive effect of Finnsheep breeding in crossbreeding schemes: Ewe productivity under n ccelerted lmbing system. Cn. J. Anim. Sci. 70:

58 Fhmy, M.H. 1990b. Growth, fertility, prolificcy nd fleece weight of Boorool, Romnov nd Finnsheep first nd bck cross with the DLS breed. Proc. 4th World Congr. Genet. Appl. Livest. Prod. XV: Fhmy, M.H. ; Dufour, J.J The ccumultive effect of Finnsheep breeding in crossbreeding schemes: Reproductive performnce. Cn. J. Anim. Sci. 68: Fhmy, M.H. ; Flipot, P.M.; Wolynetz, M.S.; Comeu, J.E Postwening growth rte nd feed conversion rtio of lmbs fed diets bsed on concentrte versus roughges. Cn. J. Anim. Sci. 69: Fhmy, M.H. ; Boucher, J.M.; Poste, L.M. ; Gregoire, R. ; Butler, G. ; Comeu, J.E Growth, feed conversion rtio, crcss composition nd sensory qulity of lmbs from prolific nd stndrd breeds nd crosses fed diets with different protein supplements. (In press) Hckett, A.J.; Wolynetz, M.S Reproductive performnce of Finnish Lndrce nd Suffolk sheep mintined indoors yer-round. J. Anim. Sci. 60: Ivn, M Effect of funtion on ruminl solubility nd liver content of copper in sheep fed low or high copper diets. J. Anim. Sci. 66: Jeffcote, I. A.; Rwlings, N.C.; Howell, W.E Durtion of the breeding seson nd response to reproductive mnipultion in five breeds of sheep under Northern Pririe conditions. Theriogenology 22: Kennedy, A.D.; Belluk, B.M Growth nd crcss composition of rm lmbs treted with clonidine. Cn. J. Anim. Sci. 67: Lirette, A.; Seone, J.R.; Minvielle, F. ; Froehlich, D Effect of breed nd cstrtion on conformtion, clssifiction, tissue distribution, composition nd qulity of lmb crcsses. J. Anim. Sci. 58: Mijl, K History, recent development nd uses of Finnsheep. J. Agric. Sci. Finl. 60: Mthewson, W.G. ; Mynrd, E.G.; McKenzie, D.R Performnce of four crossbred ewe types under two mngement systems. Cn. J. Anim. Sci. 67: (Abstrct) McClellnd, L.A Wool qulity of ewe lmbs sired by Romnov, Finnish Lndrce, Dorset nd Western Rnge rms. Cn. J. Anim. Sci. 69:273. (Abstrct) Mukhoty, H. ; Peters, H.F Influence of breed nd sex on muscle weight distribution of sheep. J. Anim. Sci. 55(Suppl. 1):530. (Abstrct) Rwlings, N.C Reproductive ctivity in Finnish Lndrce x Rmbouillet ewes exposed to vrious dylength cycles pplied over periods of six months. Theriogenology 28:

59 Rwlings, N.C.; Jeffcote, I. A.; Howell, W.E Response of purebred nd crossbred ewes to intensified mngement. J. Anim. Sci Snford, L.M. ; Plmer, W.M. ; Howlnd, B.E Chnges in the profiles of serum LH, FSH nd testosterone, nd in mting performnce nd ejculte volume in the rm during the ovine breeding seson. J. Anim. Sci. 45: Snford, L.M. ; Beton, D.B.; Howlnd, B.E.; Plmer, W.M Photoperiod induced chnges in LH, FSH, prolctin nd testosterone secretion in the rm. Cn. J. Anim. Sci. 58: Shresth, J.N.B. ; Heney, D.P Genetic bsis of vrition in reproductive performnce. 2. Genetic correltion between gesttion length nd prolificcy in sheep. Anim. Reprod. Sci. 23: Shresth, J.N.B. ; Vesely, J. A Evlution of estblished breeds of sheep in Cnd for dily gin nd body weights. Cn. J. Anim. Sci. 66: Shresth, J.N.B.; Peters, H.F.; Heney, D.P Growth performnce of lmbs sired by rms of the Est Friesin, Finnish Lndrce, lie de Frnce nd Suffolk breeds. Cn. J. Anim. Sci. 62: Shresth, J.N.B.; Fiser, P.S.; Lngford, G.A.; Heney, D.P Influence of breed, birth dte, ge nd body weight on testiculr mesurements of growing rms mintined in controlled environment. Cn. J. Anim. Sci. 63: Shresth, J.N.B.; Heney, D.P.; Fiser, P.S.; Lngford, G.A Influence of breed, birth dte, ge nd body weight on liner body mesurements of growing rms mintined in controlled environment. Cn. J. Anim. Sci. 64: Vesely, J. A Performnce of progeny of Finnish Lndrce nd Dorset Horn rms mted to ewes of vrious breeds nd crosses. Cn. J. Anim. Sci. 58: Vesely, J. A.; Swierstr, E.E Yer-round breeding of crossbred Dorset or Finnish Lndrce ewes using synthetic light regimen. J. Anim. Sci. 61: Vesely, J. A.; Swierstr, E.E Reproductive prmeters of crossbred ewe lmbs sired by Romnov, Finnish Lndrce, Dorset nd Western Rnge rms. J. Anim. Sci. 62: Vesely, J. A.; Swierstr, E.E Reproductive trits of ewe lmbs representing eight genetic types born in winter, spring, summer nd fll. J. Anim. Sci. 65: Wlton, P. ; Robertson, H.A Reproductive performnce of Finnish Lndrce ewes mted twice yerly. Cn. J. Anim. Sci. 54:

60 AUTHOR INDEX Ainsworth, L, 33 Beton, D. B. 36 Belluk, B. M. 36 Bernon, D. E. 28 Boucher, Jr.M, 18 Butler, G.. 18 Cstonguy, F., 22, 23 Chiquette, J,. 21 Comeu, J.E., 15,18 Dufour, J.J., 9, 21, 22, 23 Estrd, R., 23 Fhmy, M.H., 4, 5, 7, 9, 11, 13, 16, 17, 18 Fiser, P.S., 26, 28 Flipot, P.M., 15 Froehrlich, D., 20 Gregoire, R., 18 Hckett, A.J., 30 Heney, D.P., 25, 26, 28, 34 Howell, W.E., 38, 39 Howlnd, B.E., 35, 36 Ivn, M., 33 Jeffcote, I. A., 38, 39 Kennedy, A.D., 36 Lngford, G.A., 26, 28 Lirette, A., 20 McKenzie, D.R., 3 Mijl, K., 1 Mthewson, W.G., 3 Mynrd, E.G., 3 McClellnd, L.A., 45 Minvielle, F., 20, 21, 22, 23 Mukhoty, H., 42 Plmer, W.M., 35, 36 Peters, H.F., 25, 42 Poste, L., 18 Rwlings, N.C., 38, 39, 40 Robertson, H.A., 24 Snford, L.M., 35, 36 Sele, M.E., 2 Seone, J.R., 20 Shresth, J.N.B., 25, 26, 28, 32, 33, 34 Swiertr, E.E., 43, 44 Vesely, J. A., 32, 42, 43, 44 Wlton, P., 24 Wolynetz, M.S., 15, 30 50

61 Age sexul mturity, 21, 22, 23, 45 body weight/dy of, 4, 41 Animl model, 33, 36 Birth weight, 6, 19, 27, 34 Body composition, 4, 36 Body mesurements, 4, 28, 30 Body weight, 9, 23, 25, 32, 34, 41, 45 Breeding seson, 33, 38, 39 SUBJECT INDEX Crcss composition, 4, 6, 11, 12, 18, 19, 20, 37, 42 Crcss grde, 42 Crcss mesurements, 4, 5, 6, 11, 12 Conception rte, 10 Crosses with - Boorool, 22, 23 - Columbi, 39, 40 - DLS, 4, 5, 7, 11, 12, 13, 14, 15, 16, 17 Dorset, 44 - N.C. Cheviot, 3 - Rmbouillet, 38, 39, 40 Romnov, 44 - Suffolk, 11, 12, 15, 20, 21, 39, 40 Dressing percentge, 7, 11, 12, 19, 20, 37 Economics, 3, 12, 13 Feed conversion rtio, 6, 7, 36, 37 Feeding mngement, 11, 19 Fertility, 3, 5, 16, 17, 18, 21, 22, 23, 30, 31, 33, 38, 39, 40, 44 Fleece chrcteristics, 7, 17, 18, 45, 46 Genotype x Feeding interction, 15 Gesttion length, 9, 10, 23, 34, 38, 39 Growth, 4, 11, 12, 15, 17, 19, 20, 32, 36, 37 Heterosis, 8, 22 Hormones, 21, 22, 33, 35, 38, 39 Lmbing intervl, 16, 17, 24 Lmbing seson, 5 Lproscopy, 13, 14 Light regimen, 31, 36, 40, 41, 43 Litter size, 10, 21, 44, 45 Litter weight, 5, 16, 17, 23 51

62 Mngement systems, 3, 16, 17, 24, 30, 34, 35, 39, 40, 43, 44 Met qulity, 18, 19, 20 Mortlity, 3, 8, 10, 13, 14, 16, 17, 22, 23, 39, 43, 45 Multiple births, 34 Origin, 1, 2 Ovultion rte, 10, 13, 14, 21, 22, 23, 44, 45 Productivity, 3, 16, 17, 22, 23, 24, 33, 40, 43 Prolificcy, 5, 9, 10, 14, 16, 17, 18, 21, 22, 30, 31, 34, 39, 40, 43 Repetbility, 13, 14 Reproduction, 9, 33 Sexul behvior, 28 Testiculr mesurements, 26, 27 Wening weight, 6, 19, 23 Wool, 7, 18 52

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