SOW PRODUCTIVITY TRAITS OF CROSSBRED SOWS 1,2

SOW PRODUCTIVITY TRAITS OF CROSSBRED SOWS 1,2 K. J. Drewry Purdue University, West Lafayette, IN 47907 Summary Bar breed, sw crss and breed grup effects were evaluated fr sw prductivity traits including cnceptin rate and litter averages fr: litter size, pig livability, pig weight and litter weight. The litters were frm crssbred Durc x Yrkshire (DY), Hampshire Yrkshire (HY) and Landrace Yrkshire (LY) sws mated t purebred Durc (DD), purebred Hampshire (HH), and crssbred Durc x Hampshire and Hampshire x Durc (DH) bars. Litter average recrds were measured fr 380 litters represented at marketing. Cnceptin rate averaged 95.1%, thrugh five 30-day breeding perids, fr the 505 sw expsures. Differences in cnceptin rate amng the different bar and sw crss grups were nt significant. Bar breed effects were significant nly fr ne trait-pig market weight; whereas sw crss effects were significant fr all litter size traits. The DY sws had the largest litter sizes and weights at 0, 35 and 210 days. Litters frm DY and LY sws had 9.8 and 14.4%, respectively, greater livability at 35 days than litters frm HY sws. On a per litter marketed basis, the DY sws exhibited advantages in litter weight per sw ver HY and LY sws, respectively, f 12.6 and 7.3 kg at 35 days, and 208 and 102 kg at 210 days. Breed grup effects were significant fr all litter average traits, except litter birth weight and pig weaning weight. The DD DY grup had the largest litter sizes and weights at 0, 35 and 210 days. (Key Wrds: Swine, Specific Crsses, Crssbreeding, Reprductin, Sw Prductivity.) I ntrdutin Swine prductin systems shuld capital- Jurnal Paper N. 7480, Purdue Univ. Agri. Exp. Sta. 2 Date derived frm the Purdue Univ. cntributing prject t NC-103 reginal prject, Genetic Imprvement f Efficiency in the Prductin f Quality Prk. 242 ize n the genetic differences that exist within and amng breeds. The ecnmic returns frm a swine enterprise depend largely n prductivity f the sw herd, usually measured as number f pigs weaned r marketed per sw per year. Sw prductivity is a functin f fertility, litter size, pig livability and pig grwth rate, and is affected by factrs such as age. The cmpnent traits f sw prductivity have lw t medium heritabilities (Craft, 1958). Swine crssbreeding studies, dating frm the 1930's using bth inbred and nninbred animals, shw that hetersis fr reprductive traits, litter size, pig livability, pig weight and litter weight ranges frm 5 t 25%, dependent upn breeds used in the crss (Winters etal., 1935; Lush etal., 1939; Chambers and Whatley, 1951; Bradfrd et al., 1953; Whatley et al., 1954; Fredeen, 1957; O'Ferrall et al, 1968; Jhnsn and Omtvedt, 1975; Nelsn and Rbisn, 1976; Yung et al, 1976; Jhnsn et al., 1978). The bjectives f this study were: (1) t measure lngevity and prductivity fr three specific tw-breedcrss sws, (2) t evaluate the effects f purebred and crssbred bars, and (3) t evaluate the specific cmbinatins f bar and sw breeds and crsses represented. Materials and Methds Data fr this study were cllected at the Davis-Purdue Agricultural Center in eastern Indiana during the years 1974 t 1977. The data included breeding efficiency and litter average recrds f crssbred DY, HY and LY sws mated t purebred DD, purebred HH and crssbred DH r HD bars. In the crss, bar breed is given first. The term bar breed was used t identify this classificatin even thugh ne f the bar grups was a crss. Breed designatins used were: D = Durc, H = Hampshire, L = Landrace and Y = Yrkshire. The study was initiated with 117 gilts farrwed in January and February 1974. The 41 DY, 42 HY and 34 LY gilts were frm 17 DY, 17 HY and 13 LY litters. Gilt selectin was based n within crss (DY, HY and LY) 100- JOURNAL OF ANIMAL SCIENCE, Vl. 50, N. 2, 1980

SWINE CROSSBREEDING 243 day weight rati, underline and structural sundness. The dams f these crssbred gilts were frm a grup f 66 purebred Yrkshire gilts, representing 22 sire grups frm seven Indiana breeders. The three Yrkshire gilts per sire grup were nrmally litter-mates, and were randmly assigned ne each t purebred Durc, purebred Hampshire r purebred Landrace bar grups fr pasture mating. Three bars f each breed were used. The Durc and Hampshire bars were purchased at the July 1973 Indiana Bar Test Statin Sale and the Landrace bars were purchased at the July 1973 Landrace Summer Type Cnference Sale. All bars, except tw half-sib Landrace bars, were unrelated. The Landrace bars were "dmestic" Landr~ce. Gilts f each crss were assigned by age t early, middle and late farrwing grups. Gilts in each farrwing grup were randmly assigned.fr the duratin f the study t either DD, HH r DH bar mating grups. Fur bars f each type (fur DD, fur HH, tw DH and tw HD), farrwed in mid-january 1974, were purchased and used fr the duratin f the study. The DH crssbred bars were half-fibs t tw f the DD bars, and the HD bars were half-sibs t tw f the HH bars. The crssbred gilts were pasture mated fr 30 days. First matings fr the early, middle and late farrwing grups were made in September 1974, Nvember 1974 and January 1975, respectively, fr sws in the early, middle and late farrwing grups. The schedule prduced tw litters per sw per year, with sws being mated n secnd estrus after weaning. Nnpregnant and structurally unsund sws were culled. Hwever, management cnsideratins dictated that n'npregnant sws nt be culled after the furth farrwing seasn. In this study, parity (litter number) was cmpletely cnfunded with sw age and partially cnfunded with seasns and years. Pigs were weighed and ear ntched within 24 hr after farrwing. Male pigs were castrated prir t 10 days f age. Creep-feed was ffered at 3 weeks. All pigs within a farrwing grup (early, middle r late) were weaned when the average age was 35 days. All pigs prduced in the study were fed ut and sld fr slaughter. Pig weaning (35-day) and market (210-day) weights were calculated assuming linearity f grwth, as: actual weight minus birth weight divided by actual age, multiplied by either 35 r 210, plus birth weight. r~ z r,1 z r~ z,...1 r,1,1 e~ +1 +1 +1 +1 +1 ~ +L +1 e,i +1,q. t~ +1 +1 4+1 +1 +1 +1 ~-, e,i r r~ r~ ~'~ 44 +1 +1 +1 +1 pp+ i,~ p++l +1 +1.vl,,4-0 0~.,.,.,4 +1 ~ +1 +1 ~ +l +1 -;-I +l +1 e~,,.-i +l +1 +1 +1 ~1

244 DREWRY TABLE 2. LEAST-SQUARES MEANS AND STANDARD ERRORS FOR LITTER SIZE Surce N. Farrwing a 35 days 210 days (no.) Mean 380 12.0 _+.14 8.8 +.15 8.3 -+.15 Breed grup ** ** ** DD DY 47 13.4.38 10.2 +.39 9.7 -+.39 DD X HY 44 11.9 -+.39 8.4 +.40 8.0.40 DD X LY 34 10.8 -+.44 8.3 +.46 8.0 +.46 HH DY 56 12.4 -+.34 9.3 -+.36 8.9 -+.35 HH X HY 39 12.1 -+.41 7.8.43 7.3 -+.43 HH X LY 35 10.9 ~.44 9.1 -+.45 8.9 +.45 DH X DY 44 12.6 +.39 9.1 +.40 8.9 -+.40 DH X HY 47 12.9 -+.38 7.9 -+.39 7.2.39 DH X LY 34 11.0.44 8.9.46 7.9 +.46 Bar breed r crss NS NS NS DD 125 12.1.23 9.0.24 8.6 +-.24 HH 130 11.8.23 8.8 +.24 8.4 -+.23 DH 125 12.1 +.23 8.6 -+.24 8.0 +.24 Sw crss * * * * * * DY 147 12.8.21 9.5 +-.22 9.2.22 HY 130 12.3 -+.23 8.0 +-.24 7.5.2.3 LY 103 10.9 -+.25 8.8 -+.26 8.3.26 attal pigs, dead and live. *P.05. * * P.O1. Sw cnceptin rate (percentage sws farrwing f sws expsed) was btained using discrete cdes f: 0 = nt farrwing and 1 = farrwing, fr each sw expsed. Litter average prductin recrds included: (1) litter size, and pig and litter weights at O, 35 and 210 days and (2) pig livability at 35 days, and frm 35 t 210 days. Analysis. Cnceptin rate and litter average recrds were analyzed using mixed mdel, least-squares prcedures f Harvey (1976). Breed grup was derived by cmbining bar breed and sw crss classes. Farrwing grup, breed grup, bar breed, sw crss and litter number were cnsidered as fixed effects. One analysis included main effects f farrwing grup (G), bar breed (B), sw crss (S) and all tw-way interactins. A secnd analysis included main effects f farrwing grup-bar breed-sw crss (GBS), sws/gbs and litter number (L). The sws/gbs mean squares were used t test farrwing grup (G), bar breed (B), sw crss (S) and GxB, GxS and BxS interactins. A third analysis included main effects f bar breed-sw crss (BS), sws/bs and litter number (L). The sws/bs mean squares were used t test breed grups (BS). Litter number (L) was tested using the remainder mean squares. Earlier preliminary analyses shwed nnsignificant interactins invlving G, B, S and L. Least-squares means and apprximate standard errrs fr breed grup, bar breed r crss and sw crss were derived using the GBS least squares means and the amng sws/gbs mean squares. Cnceptin rate was analyzed fr 505 sw expsures thrugh five matings. Litter average recrds were analyzed fr the 380 sws with litters represented at marketing thrugh fur farrwings. Results and Discussin Cnceptin Rate. Average cnceptin rate was 95.1% fr the 505 sw expsures thrugh five breedings (table 1). Significant farrwing grup effects were bserved, with cnceptin rate averages f 93.3, 98.9 and 93.0%, respectively, fr sws in the early, middle and late farrwing grups. Average cnceptin rates f

SWINECROSSBREEDING 245 TABLE 3. LEAST-SQUARES MEANS AND STANDARD ERRORS FOR PIG L1VABILITY At 35 35 t Surce N. days a 210 days b (%) Mean 380 73.9 -+ 1.06 93.4.67 Breed grup ** ** DD DY 47 76.9 -+ 2.78 94.6 1.75 DD X HY 44 71.5 2.87 92.5 +- 1.81 DD X LY 34 76.5 +- 3.27 96.0 +- 2.06 HH DY 56 76.5 2.55 94.7 1.61 HH X HY 39 65.2 3.05 90.8 -+ 1.93 HH X LY 35 83.5 -+ 3.22 97.3 2.03 DH X DY 44 73.7 t 2.87 96.9 1.81 DH X HY 47 60.9 2.78 90.8 1.75 DH X LY 34 80.8 + 3.27 87.6 2.06 Bar breed r crss NS NS DD 125 75.0 + 1.70 94.3 1.08 HH 130 75.1 + 1.67 94.3 + 1.05 DH 125 71.8 1.70 91.7 1.08 Sw crss * * * DY 147 75.7 -+ 1.57 95.4 +-.99 HY 130 65.9 1.67 91.4 1.05 LY 103 80.3 1.88 93.6 1.18 apercent live pigs at 35 days f ttal pigs farrwed (dead and live). bpercent pigs marketed f pigs weighed at 35 days. *P.05. **P.O1. 88.7, 97.9, 97.6, 94.8 and 96.4%, respectively, were bserved fr litters ne thrugh five. A high repeatability f pregnancy rate is suggested by the high mean values fr litters tw thrugh five. Hwever, it is nt pssible t state whether the higher cnceptin rates fr litters tw thrugh five are due t culling infertile gilts and(r) sws, r represents an effect f age r parity. The 88.7% average cnceptin rate fr first litter gilts is similar t the 87% cnceptin rate fr crssbred gilts reprted by Hltrnann et al. (1975), but smewhat larger than the 81.1% cnceptin rate fr crssbred gilts reprted by Jhnsn et al. (1978). Cnceptin rates f 97.7 and 82.7%, respectively, fr the DY and HY first litter gilts are apprximately 10% larger than cnceptin rates f 83.4 and 76.1% fr DY and HY first litter gilts reprted by Jhnsn et al. (1978). Bar breed, sw crss and breed grup effects were nnsignificant fr cnceptin rate. Since culling did ccur n the basis f cnceptin rate, cmparisns amng bar breed and sw crss grups fr litters 2 t 5 and fr verall cnceptin (table 1) are biased. In this study, the number f litters prduced per riginal gilt selected was 4.65, 4.17 and 4.09, respectively, fr DY, HY and LY sws; and 4.21, 4.33 and 4.42, respectively, fr sws mated t DD, HH and DH bars. Litter Size. Breed grup differences were significant fr litter size at 0, 35 and 2t0 days (table 2). The largest litters were prduced by DD DY sws, whereas the smallest litters at O, 35 and 210 days were prduced by DD LY, HHx HY and DHx HY sws, respectively. These differences in litter size between the best and the prest breed grups are similar t ranges in litter size at birth and weaning fr varius breed cmbinatins, bserved by O'Ferrall et al. (1968), Hltmann et al. (1975) and Nelsn and Rbisn (I976). Bar breed effects were nnsignificant fr litter size at 0, 35 and 210 days. The litter averages f 9.0 and 8.8 pigs fr DD and HH bars at weaning are similar t averages f 8.9 and 8.6 pigs at weaning bserved fr these bar breeds by Nelsn and Rbisn (1976). Sw crss differences were significant fr litter size at 0, 35 and 210 days. The DY sws had the largest litters at all ages while LY sws were prest at 0 but secnd at 35 and 210 days. Nelsn and Rbisn (1976)bserved nnsignificant breed f dam differences fr litter size at farrwing (live pigs) and weaning amng reciprcal crss sws invlving the Durc, Hampshire and Yrkshire breeds (six crsses). Pig Livability. Breed grup, bar breed and sw crss means and standard errrs fr pig livability are presented in table 3. Significant breed grup differences were bserved fr pig livability. At 35 days, the HHXLY and DHx LY grups, thse pssessing 100% hetersis, exhibited the highest livability, and the HHX HY and DH HY grups, pssessing 50% and 75% hetersis, respectively, exhibited the lwest livability. Livability frm 35 t 210 days was highest fr HH and DH and lwest fr DH HY and DH LY grups. Bar breed effects were nnsignificant fr pig livability. Significant sw crss differences were bserved fr pig livability at 35 days, with livability f pigs frm DY and LY sws exceeding that f pigs frm HY sws by 9.8 and

246 DREWRY TABLE 4. LEAST-SQUARES MEANS AND STANDARD ERRORS FOR PIG WEIGHT Surce NO. Birth a 35 days 210 days (kg) Mean 380 1.28.02 7.63.08 108.3.38 Breed grup ** NS * * DD DY 47 1.25.~.04 7.58 +-.20 108.8 1.01 DD X HY 44 1.23,04 7.77.21 109.2 ~ 1.04 DD X LY 34 1.34.05 7.66.24 110.5 1.18 HH X DY 56 1.36.04 7.93.19 111.9.92 HH X HY 39 1.14.05 7.30.22 103.3 1.11 HH X LY 35 1.43.05 7.75.24 110.0 1.17 DH X DY 44 1.24 ~.04 7.82.21 109.6 1.04 DH HY 47 1.11.04 7.41.20 103.2 1.01 DH X LY 34 1.41 -*.05 7.48.24 108.5 1.18 Bar breed r crss NS NS * DD 125 1.28.03 7.67.12 109.5.62 HH 130 1.31.03 7.66.12 108.4 :t.61 DH 125 1.25.03 7.57 +-.12 107.1.62 Sgw crss ** NS ** DY 147 1.28.02 7.78.11 110.1.57 HY 130 1.16.03 7.50.12 105.2.61 LY 103 1.39.03 7.63.14 109.6,68 attal pigs, dead and live. *P.05. **P.O1. 14.4%, respectively. Nelsn and Rbisn (1976) bserved nnsignificant breed f dam differences in pig survival t weaning. Pig Weight. Significant breed grup differences were bserved fr birth and 210 day weights (table 4). The HHX LY and DHX LY grups, each with 100% hetersis, had the heaviest birth weight, 1.42 kg, and the DHx HY grup, with 75% hetersis had the lightest birth weight, 1.11 kilgrams. At 210 days the HHx DY and DDX LY grups were the heaviest, averaging 111.9 and 110.5 kg, respectively, and the HH HY and DHx HY grups were the lighest, averaging 103.3 and 103.2 kg, respectively. Nelsn and Rbisn (1976) bserved significant breed grup differences fr birth weight f live pigs, with the Px HD pigs weighing 1.54 kg and the PXHY pigs weighing 1.33 kilgrams. Significant bar breed and sw crss differences were bserved fr litter average pig weight at market. Pigs frm DD and HH bars were 2.4 and 1.3 kg heavier than thse frm DH bars, and pigs frm the DY and LY sws were 4.9 and 4.4 kg heavier than pigs frm HY sws. At birth, pigs frm LY sws had weight advantages f.11 and.23 kg ver pigs frm DY and HY sws, respectively. Birth weight was nt adjusted fr litter size, and thus differences in litter size (table 2) is the mst likely basis fr the differences in birth weight. Litter Weigbt. Breed grup, bar breed and sw crss least-squares means and standard errrs fr average litter weights at birth, 35 days and 210 days are presented in table 5. Breed grups effects were significant fr average litter weight at 0, 35 and 210 days. Heaviest litters at birth were bserved with the HHx DY and DDX DY grups, whereas the lighest litters were bserved frm the HHxHY grups. The DDXDY litters were heavier at 35 and 210 days. Nelsn and Rbisn (1976)bserved a nnsignificant difference f 225 kg (445 t 680 kg) fr ttal litter 140-day weight with 16 breed grups. Hltmann et al. (1975) reprted significant differences fr average weight f weaned pigs after tw litters (farrwing percentages x litter weight at 21 days) fr 28 tw-

SWINE CROSSBREEDING 247 TABLE 5. LEAST-SQUARES MEANS AND STANDARD ERRORS FOR LITTER WEIGHT Surce N. Birth a 35 days 210 days Mean 380 15.1.22 68.0 + 1.0 907 + 16 Breed grup ** ** ** DD DY 47 16.7 +.56 78.5 + 2.7 1057 -+ 44 DD HY 44 14.4.58 66.6 + 2.8 886 43 DD LY 34 14.2.66 63.4 + 3.2 880 49 HHX DY 56 16.8 ~.52 74.2 + 2.5 1003 38 HH HY 39 13.8.62 59.2 3.0 760 46 HH X LY 35 15.5 +.65 70.9 + 3.1 980 48 DH X DY 44 15.3 +.58 71.0 2.8 972 + 43 DH X HY 47 14.4.56 60.2 2.7 753 + 44 DH LY 34 15.0.66 67.5 3.2 866 + 49 Bar breed r crss NS NS NS DD 125 15.1.35 69.5 1.7 941 25 HH 130 15.4 -+.34 68.1 -+ 1.6 918 -+ 25 DH 125 14.9.35 66.2 -+ 1.7 863 25 Sw crss * * * * * * DY 147 16.3 +.32 74.6 -* 1.5 1011 + 23 HY 130 14.2 +.34 62.0 s 1.6 803 25 LY 103 14.9 +.38 67.3 1.8 909 28 ~kg) attal pigs, dead and live. *P.05. **P.01. breed crss sws mated t Pland China bars. The range in average weight f weaned pigs was 28.2 kg, 80.6 kg fr the P LY breedcrss and 52.4 kg fr the Pland Tamwrth-Large Black breedcrss. Bar breed effects were nnsignificant fr average litter weight at birth, 35 days and 210 days. Significant sw crss differences were bserved fr average litter weights at 0, 35 and 210 days. Litters frm DY sws had weight advantages ver litters frm HY and LY sws, respectively, f 2.1 and 1.4 kg at birth, 12.6 and 7.3 kg at 35 days, and 208 and 102 kg at 210 days. Litters frm LY sws had weight advantages ver litters frm HY sws f 5.3 and 106 kg, respectively, at 35 and 210 days. With prices f $2.646/kg at 35 days and $.882/kg at 210 day s the advantage f DY sws ver HY and LY sws in ttal litter weight wuld result in differences in grss incme per sw f $33.34 and $19.32 at 35 days, and $183.46 and $89.96 at 210 days. Literature Cited Bradfrd, G. E., A. B. Chapman and R. H. Grummer. 1953. Perfrmance f hgs f different breeds and frm straightbred and crssbred dams n Wiscnsin farms. J. Anita. Sci. 12:582. Chambers, Dyle and J. A. Whatley, Jr. 1951. Hetersis in crsses f inbred lines f Durc swine. J. Anim. Sci. 10:505. Craft, W. A. 1958. Fifty years f prgress in swine breeding. J. Anita. Sci. 17r Fredeen, H. T. 1957. The genetic imprvement f swine. Anim. Breed. Abstr. 26:229. Harvey, W. R. 1976. Prgram write-up fr leastsquares and maximum likelihd general purpse prgram. The Ohi State Univ. (Mime). Hltmann, W. B., M. H. Fahmy, T. M. Maclntyre and J. E. Mxley. 1975. Evaluatin f female reprductive perfrmance f 28 ne-way crsses prduced frm eight breeds f swine. Anim. Prd. 21:199. Jhnsn, R. K. and I. T. Omtvedt. 1975. Maternal hetersis in swine: reprductive perfrmance and dam prductivity. J. Anim. Sci. 40:29. Jhnsn, R. K., I. T. Omtvedt and L. E. Waiters. 1978. Cmparisn f prductivity and perfrmance fr tw-breed and three-breed crsses in swine. J. Anim. Sci. 46:69. Lush, J. L., P. S. Shearer and C. C. Culbertsn. 1939. Crssbreeding hgs fr prk prductin. Iwa Agr. Exp. Sta. Bull. 380. Nelsn, R. E. and O. W. Rbisn. 1976. Cmparisns f specific tw- and three-way crsses f swine. J. Anim. Sci. 42:1150. O'Ferrall, G. J. Mre, H. O. Hetzer and J. A. Gains.

248 DREWRY 1968. Itetersis in preweaning traits f swine. J. Anita. Sci. 27:17. Whatley, J. A., Jr., D. Chambers and D. F. Stephens. 1956. Using hybrid vigr in prducing market pigs. Oklahma Agr. Exp. Sta. Bull. 415. Winters, L. M., O. M. Kiser, P. S. Jrdn and H. W. Peters. 1935. A six years study f crssbreeding swine. Minnesta Agr. Exp. Sta. Bull. 320. Yung, L. D., R. K. Jhnsn and I. T. Omtvedt. 1976. Reprductive perfrmance f swine bred t prduce purebred and tw-breed crss litters. J. Anita. Sci. 42:1133.