Interntinl Jurnl f Pultry Science 5 (4): 337-343, 006 ISSN 68-8356 Asin Netwrk fr Scientific Infrmtin, 006 Effect f Chelted Clcium Prteinte Fed in the Mternl f Turkey Breeders n Emry Crdic Physilgy nd Pult Qulity 3 V. L. Christensen, J.L. Grimes, R.D. Rwlnd nd D.T. Ort Deprtment f Pultry Science, Cllege f Agriculture nd Life Sciences, Nrth Crlin Stte University, Rleigh, Nrth Crlin 7695-7608, USA 3 Chelted Minerls Crprtin, 330 West 900 Suth, Slt Lke City, Uth 8404, USA Astrct: Emry nd htchling survivl diminish s turkey reeder hens ge. Recent dt indicted tht chelted clcium prteinte (CCP) dditive given t turkey reeder hens imprved emry survivl s hens ged ut did nt ffect shell thickness. We hypthesized tht the mechnism y which this ccurred my e y imprved functinl shell qulity nd its cnsequent effect n crdic physilgy. T test the hypthesis, CCP ws supplemented t the diet f Lrge White turkey reeder hens fr 5 week egg prductin perid nd cmpred with cntrls withut supplementtin. Eggshell cnductnce, cnductnce cnstnts, pult grwth nd crdic physilgy were mesured t weeks 0, 8 nd 5 f prductin. Becuse elevted tempertures increse hert rtes nd reduce hert weight nd survivl, hlf f the eggs ws incuted t 37.9 C wheres the remining eggs were incuted t 37.5 C. Emrys nd pults frm the CCP grup exhiited incresed hert weights nd imprved crdic helth. The htching pults frm CCP-fed hens ls grew fster fr the first 3 d f life. We cnclude tht CCP imprves eggshell cnductnce, nd the susequent eggshell cnductnce cnstnt (k) f eggs frm turkey reeder hens. The chnge in k imprved emry crdic helth nd pult BW fter htching. Key wrds: Chelted clcium, hert, emry Intrductin As turkey reeder hens ge, emry survivl diminishes (Firchild et l., 00) nd the qulity f the htchling declines (Grimes et l., 004). Previus experiments indicted tht supplementtin f chelted clcium prteinte prduct (ClKey (CCP) Chelted Minerls Crprtin, Slt Lke City, UT) t turkey reeder hen diets, imprved the livility f emrys y decresing the numer f emrys dying t pipping (Grimes et l., 004). The imprvement ws especilly evident when the hens were lder thn 54 weeks f ge. The imprvement in emry viility ccurred independent f chnges in eggshell thickness. We speculte tht the ctins f the dded clcium my hve een n functinl rther thn physicl prperties f the eggshell r n the ctin f clcium ins directly n the hert. Functinl chrcteristics my differ ecuse cnductnce invlves nt nly shell thickness, ut includes pre numer nd crss-sectinl re (Christensen et l., 005). Alterntively, inic clcium my hve direct effect n the emry hert (Rhn et l., 980) ecuse f its effect n mycrdium ctin ptentils. Thus, the results f prir studies my ls hve een due t ther fctrs nt tested in prir studies. Incresed incutr tempertures hve een knwn fr mny yers t increse hert rtes f emrys (Muntcstle et l., 974) s well s diminish pult qulity. Therefre, the hypthesis ws prpsed tht the dditinl stress f incresed incutr temperture n crdic helth my e melirted y feeding mternl surce f chelted clcium prteinte (CCP). The CCP ws cmpred t cntrls fed limestne flur s clcium surce. Mterils nd Methds Nichls turkey reeder hens were distriuted rndmly t pens with 6 irds ech nd fed identicl turkey diets. Birds were divided int tw tretment grups with six pens eing fed the cntrl diet cntining.75% clcium frm limestne flur, nd the remining six pens eing fed the tretment diet cntining.70% clcium frm limestne flur supplemented with 0.05% clcium frm CCP (Grimes et l., 004). Pens served s the experimentl unit fr the egg prductin dt. At 3 wk f ge the hens were pht stimulted t egin n egg prductin cycle nd given the tretment diets. The diets were ville t the reeder hens n n d liitum sis eginning t pht stimultin. A ttl f 5 weeks f egg prductin ws served fr the experiment. Hens were inseminted weekly with semen frm sires f the sme ge nd strin. Eggs were cllected dily nd stred fr 3 t 5 dys prir t setting. The eggs were srted y pens then were divided rndmly int tw incutin temperture grups. One grup ws incuted t 37.5 C (C) nd the ther t 37.9 C (HI). Heted nd cntrl eggs were set in five different incutrs, nd the tretments were ssigned t different incutrs fr ech set s incutr ws nt fctr in the experiment. Within weeks 9, 7 nd 4 f 337
Christensen et l.: Emrynic Hert prductin, pprximtely 600 eggs representing ll presented. Mens tht differed significntly were tretments (c. 50/tretment cmintin) were seprted y the lest squre men prcedure. The weighed t setting nd t trnsfer t determine eggshell level f significnce ws set t P < 0.05 unless cnductnce vlues using the clirted egg technique therwise nted. (Rmnff nd Schen, 938). The functinl chrcteristic f ech eggshell (mg f wter vpr/dy/mm Hg) ws further evluted y determining the length f the incutin perid fr ech egg y nting the time ech pult htched t 6 h intervls eginning t 600 h f develpment. Individul eggs frm weeks 9, 7 nd 4 were the experimentl unit fr the Results Hert rtes: HI incresed hert rtes in d emrys nd intercted with mternl dietry clcium t ffect hert rtes in 0 d emrys (Tle ). At 0 d HI incresed hert rtes if the dms were fed the C diet, ut HI lwered hert rtes if the dms were fed CCP. At 4 eggshell mesurements. These dt were used t d f develpment th CCP nd HI incresed hert rtes cmpute f the cnductnce cnstnt (Rhn, 98). The cmpred t cntrls. vlue fr k indictes the prper time fr htching tht ptimizes htchling mturity (Christensen et l., 005) Hert weights: HI lwered hert weights in 7 d depending upn egg weight nd eggshell cnductnce. emrys regrdless f diet (Tle ). At 8 d CCP At weeks 0, 8 nd 5, emry hert rtes were reduced hert weights cmpred t the Cntrl diet. In served fr rndmly selected eggs using n 3 d ld pults, diet nd temperture intercted such tht scillscpe designed fr incuting eggs (Avitrnics, mternl CCP incresed hert weights in pults UK). Hert rtes were recrded fr 0 eggs per diet nd expsed t HI t e equivlent t thse frm C, ut when temperture tretment cmintin. Rtes were dms were fed the cntrl diet, HI temperture recrded t 4-d intervls etween nd 4 d f depressed hert weights cmpred t C. develpment. Rndmly selected individul eggs representing ll pens in tretment were the Crdic physilgy: Emry crdic glycgen experimentl unit fr the hert rte nlysis (N = 80 per cncentrtins were nt ffected y diet r incutr d). Within ech f the three trils, hert tissue ws cllected dily t incutin dys 7 nd 8 frm temperture (Tle 3), ut HI elevted mycrdil lctte rndmly selected emrys s well s frm pults t 3 in emry herts cmpred t C, nd dietry CCP d psthtching. Rndmly selected individul prevented lctte ccumultin in mycrdium t 7 d f emrys/pults representing ll pens were the emry develpment cmpred t thse in emrys experimentl units fr the tissue nlyses (N = 36 per d). frm hens fed the Cntrl diet. N diet effects were seen Bld ws cllected fllwing decpittin, the dy with t 8 d. nd withut ylk ws weighed (nerest 0.0g), herts were remved nd weighed, nd crdic glycgen nd lctte cncentrtins were susequently mesured (Tullett et l., 98). On ech f the smpling weeks fllwing htching, 36 pults frm ech f the tretments (44 ttl pults) were plced int ttery rder (Petersime, Gettysurg, OH 4538). The pens were rndmly ssigned t tretments with 3 pens f pults ech per tretment cmintin (n = 08 per tretment). The pults were weighed individully t plcement, 3 nd 7 d, nd the feed cnsumed per pen (n = 9 per tretment) ws determined ver the sme time perids. Individul pults were the experimentl unit fr the BW dt, nd Eggshell cnductnce: ry CCP incresed eggshell cnductnce cmpred t the Cntrl diet (Tle 4), nd diet nd temperture intercted t ffect htching times. The CCP diet shrtened develpmentl times f cntrl emrys y nerly 4 h cmpred t Cntrl. When emrys were expsed t HI, the verll develpment times were shrter ut did nt differ etween diets. Cnductnce cnstnts (k) were cmputed s functin f egg weight, eggshell cnductnce nd htching times (Rmnff nd Schen, 938) CCP incresed k cmpred t Cntrl. hd n effect n egg prductin rtes (dt nt shwn) r egg weights in the current experiment. pens were the experimentl unit fr the feed cnsumptin dt. Dt were nlyzed s diets y tempertures fctril rrngement (Christensen et l., 005). Dt were srted y dy f develpment prir t nlysis. Tril (htches r weeks f egg prductin) ws used s fixed fctr in the nlysis. Individul ird dt were used in the nlysis fr ll vriles. Pult grwth dt ls utilized pen s fixed fctr in the nlysis, ut n significnt pen effects were seen s they will nt e Pult BW: Pult qulity ws tested y weighing htchlings t htching nd 3 d fllwing htching (Tle 5). A diet y temperture interctin ffected the pult weights. Amng pults frm hens fed the Cntrl diet, HI reduced htchling BW cmpred t C, ut CCP intercted with temperture nd incresed BW t e equivlent with the cntrls. N differences were nted in feed cnsumptin (dt nt shwn). HI incresed residul ylk t htching cmpred t C. 338
Christensen et l.: Emrynic Hert Tle : Hert rte (ets per min, n = 80) f turkey emrys in eggs frm dms fed chelted clcium prteinte (CCP) then expsed t high incutin tempertures (37.9ºC ) cmpred t cntrls (37.5ºC) Pult ge 3 ------------------------------------------------------------------------------------ Temperture 6 0 4 CCP 35 9 4 Cntrl 3 4 9 34 38 Cntrl 3 5 9 9 Cntrl 4 4 6 Temperture mens 34 35 Cntrl 8 8 Men ± SEM 7 ± 3 3 ± 4 ± 3 ± Prilities NS NS NS 0.0 Temperture 0.05 NS NS 0.05 x Temperture NS NS 0.006 NS = CCP-treted reeder hens were fed.70% clcium s limestne flur with 0.05% chelted clcium prteinte; CON-reeder hens were fed.75% clcium. Temperture = were incuted were incuted t 37.9 C; Remining eggs were incuted t 3 37.5 C. Pult ge is the numer f dys f emry develpment. Tle : Hert weights (mg, n = 36) f turkey emrys in eggs frm dms fed chelted clcium prteinte (CCP) then expsed t high incutin tempertures (37.9 C ) cmpred t cntrls (37.5 C). Pult ge 3 ------------------------------------------------------------------------------------ Temperture 7 d emry 8 d emry 3 dys CCP 348 44 550 Cntrl 369 403 596 43 Cntrl 346 47 58 Cntrl 358 439 509 433 Temperture mens 346 Cntrl 364 Men ± SEM 356 ± 8 43 ± 9 559 ± Prilities NS 0.03 NS Temperture 0.05 NS NS x Temperture NS NS 0.0 = CCP-treted reeder hens were fed.70% clcium s limestne flur with 0.05% chelted clcium prteinte; CON-reeder hens were fed.75% clcium. Temperture = were incuted were incuted t 37.9 C; Remining eggs were incuted t 3 37.5 C. Pult ge = 7 dys f emry develpment = e7; htching = e8; three dys pst htching = 3d. Discussin Mternl dietry clcium ffected eggshell G nd susequent pult helth vi crdic physilgy, thus, we ccept ur hypthesis. Shell thickness declines (Grimes et l., 004) nd G increses (SAS Institute, 998) s hens ge, nd feeding CCP t turkey reeder hens my e mechnism t increse G nd imprve the dy weight f pults frm ging hens. The dt relting crdic physilgy nd eggshell G re nvel ut prly nt surprising. Mny envirnmentl fctrs hve een implicted in crdimypthy in perintl turkeys including diet, rpid grwth nd virl infectin (Christensen et l., 996, Mgwd nd Bry, 96, Hunsker, 97; Dewr nd Sillr, 97; Jnkus et l., 97; Onderk nd Bhtngr, 98; Frme et l., 003), ut t the uthrs knwledge, n ne hs implicted G. The ide tht the functinl prperty f eggshells my limit xygen diffusin (Rersn, 005) t the develping emry nd cnsequently lter crdic helth (Tullett, 98) my e unique t this study. 339
Christensen et l.: Emrynic Hert Tle 3: Crdic glycgen nd lctte cncentrtins (mg/g f wet tissue mss, n = 36) f turkey emrys in eggs frm dms fed chelted clcium prteinte (CCP) then expsed t high incutin tempertures (37.9 C) cmpred t cntrls (37.5 C). Pult ge 3 ------------------------------------------------------------------------------------------------- Temperture 7 d emry 8 d emry 3 dys Glycgen CCP 4.88 3.39.3 Cntrl 4.76 3.5.04 Cntrl 5.09 3..3 Cntrl 5.8 3.39.0 Men ± SEM 5.00 ± 0.0 3.9 ±.5 ± 0.04 Prilities NS NS NS Temperture NS NS NS x Temperture NS NS NS Lctte CCP 0.56 0.9 0.88 Cntrl 0.56 0.95 0.96 Cntrl 0.70 0.86 0.99 Cntrl 0.46.04 0.88 Temperture mens.0 Cntrl 0.89 Men ± SEM 0.58 ± 0.03 0.94 ± 0.0 0.99 ± 0.0 Prilities NS NS NS Temperture 0.05 0.03 NS x Temperture 0.05 NS NS = CCP-treted reeder hens were fed.70% clcium s limestne flur with 0.05% chelted clcium prteinte; CON-treted reeder hens were fed.75% clcium. Temperture = were incuted were incuted t 37.9 C; Remining eggs were 3 incuted t 37.5 C. Pult ge = 7 dys f emry develpment = e7; htching = e8; three dys pst htching = 3d. Tle 4: Functinl chrcteristics f eggs prduced y turkey hens fed tw surces f clcium Mesurement ------------------------------------------------------------------------------------------------ Initil egg Cnductnce Htching Cnductnce Temperture weight (g) (mg/d/mmhg) time (h) cnstnt CCP Cntrl 0.4 3.7 653 6.4 0. 4.3 c 647 6.43 Men 4.0 6.9 CON Cntrl 0.7 3.3 657 5.99 0.5 3.0 c 646 5.95 Men 3. 5.97 Men ± SEM 0.3 ± 0. 3.5 ± 0. 65 ± 0.5 6.03 ± 0.05 Prilities NS 0.03 0.05 0.00 Temperture NS NS 0.000 NS x Temperture NS NS 0.0 NS = CCP-treted reeder hens were fed.70% clcium s limestne flur with 0.05% chelted clcium prteinte; CON-reeder hens were fed.75% clcium. Temperture = were incuted were incuted t 37.9 C; Remining eggs were incuted t 37.5 C. Bdy nd hert weight: The pult grwth dt frm the current study shwed tht pults htching frm eggs with incresed eggshell permeility hd n dvntge in grwth fr the initil 3 d utside the shell. Incresed pult ws sscited with hevier emry herts in eggs with greter G frm CCP-fed dms. incutr tempertures ls incresed hert weights, ut when CCP ws fed n hert enlrgement ws nted. Thus, it is cncluded tht eggs with greter G shw imprved psthtching grwth nd etter crdic helth tht 340
Christensen et l.: Emrynic Hert Tle 5: Bdy nd ylk weights (g) f pults frm hens fed tw surces f clcium when expsed t higher incutin temperture Pult ge 3 ---------------------------------------------------------------------------- Temperture e7 e8 3d BW withut ylk CCP 60. 58.3 84.4 Cntrl 59.3 59.6 88.5 CON 57.9 55.9 84.7 Cntrl 6.7 60.6 78. Temperture mens 58.6 Cntrl 60.9 Men ± SEM 59.8 ± 0.5 57.4 ± 0.9 84.0 ± 0. Prility (D) NS NS 0.04 Temp 0.05 NS NS x Temperture NS 0.0 0.03 Ylk CCP 6.5.6.0 Cntrl 6.3 0..8 CON 5.7 3..6 Cntrl 5. 9.6.6 Temperture mens.4 Cntrl 9.9 Men ± SEM 5.9 ± 0.. ± 0..0 ± 0.3 (D) NS NS NS Temp (T) NS 0.03 NS x Temperture NS NS NS = CCP-treted reeder hens were fed.70% clcium s limestne flur with 0.05% chelted clcium prteinte; CON-treted reeder hens were fed.75% clcium. Temperture = were incuted were incuted t 37.9 C; Remining eggs were 3 incuted t 37.5 C. Pult ge = 7 dys f emry develpment = e7; htching = e8; three dys pst htching = 3d. enles djustment t high incutr temperture t the decresed prtein synthesis nd incresed metlism end f emry develpment. f ft, pssily sscited with liver dmge (Czrnecki et l., 975). It ws determined tht glycgen rnching Crdic physilgy: Greter G f eggs frm hens fed levels were unltered; therefre, the est explntin fr CCP ws sscited with greter hert rtes regrdless the ltered levels ws chnge in degrdtin f f incutr temperture, ut elevted tempertures glycgen (Czrnecki et l., 980). Other reprts exist fr ls incresed rtes during emry develpment in the crdimypthy effects n tissue glycgen indicting current study. Mternl dietry CCP slwed temperture- either n chnge in glycgen levels (Czrnecki et l., induced increses in hert rtes t 0 d, ut CCP 975) r decresed levels f glycgen in the pults elevted hert rtes t 4 d f develpment regrdless (Stley et l., 978). Emry crdic glycgen f temperture. Thus, it my e tht G chnges hert cncentrtins incresed in the current study nly s the rtes depending upn respirtry needs f the emry reeder hen ged (Tril effects). Hwever, lctte during the plteu stge in xygen cnsumptin. cncentrtins incresed in mycrdium f pipping emrys frm CON-fed hens ut nt in thse fed CCP. Crdic glycgen nd lctte: Erly studies in Thus, temperture nd hen ge th incresed the crdimypthy pults (Rersn, 005) nted munt f lctte fund in mycrdium suggesting excessive glycgen in vrius tissues, specificlly in left mycrdil energy metlism nd pssile muscle nd right ventriculr tissue; with the right ventricle hving ftigue my e fctrs in the reduced hert weight. Thus, greter increse in glycgen cntent (Rhn, 98). mycrdil glycgen nd lctte cncentrtins Glycgen grnules were served in lyssmes which served in the current study supprt the ide tht CCP were hypthesized t result frm lck in the citric cid imprved survivl vi crdic helth. cycle preventing the cmplete rekdwn f glycgen nd resulting in ltered heptic metlism, including Eggshell cnductnce: Previus reserch indicted n 34
Christensen et l.: Emrynic Hert reltinship etween shell thickness nd Christensen, V.L., M.J. Winelnd, D.T. Ort nd K.M. crdimypthy in turkeys (Czrnecki et l., 978). Mnn, 005. Eggshell cnductnce nd incutr Differences in the current study were due t functinl ventiltin s fctrs in emry survivl nd pult eggshell qulities f eggshell cnductnce (G) nd qulity. Int. J. Pult. Sci., 4: 88-86. eggshell cnductnce cnstnt (k) rther thn shell Christensen, V.L., M.J. Winelnd, I. Yildrum, B.D. thickness. The cnductnce prperty f n egg is Firchild, D.T. Ort nd K.M. Mnn, 005. Incutr functinl ecuse it ensures three requirements re temperture nd xygen cncentrtins during the met in timely mnner fr successful htching plteu stge in xygen uptke ffect turkey emry (Mirslimi et l., 990). The first requirement is tht n egg lses pprximtely 5% f the initil egg mss s wter vpr. He (Mirslimi et l., 990) descried the remining requirements s fllws:. the ttl munt f xygen tht will hve een cnsumed is ut 00 ml/g f egg weight, nd 3. the xygen cncentrtin in the ir cell shrtly efre pipping will hve fllen t 4% while tht f crn dixide shuld increse t ut 6%. The three cnditins ensure tht the pult htches with the chrcteristic mturity r qulity f the species. Others (Gzdinski et l., 993) indicted tht cnductnce must e dditinlly mtched t the initil egg mss nd the length f the incutin perid t determine cnductnce cnstnt (k). The k then ensures tht the htchling hs the chrcteristic mturity f the species. Acrss vin species, the prduct f cnductnce nd the length f the incutin perid were directly prprtinl t k while egg mss ws inversely relted. They prpsed tht k = 5.3 wuld crete htchling f the chrcteristic mturity f the species. Thus, k greter r smller thn 5.3 my crete htchlings f lesser qulity. It my e suggested frm the results f the current study tht feeding CCP t turkey reeder hens incresed cnductnce, shrtened htching times nd hd n effect n egg weight such tht k ws incresed. Feeding CCP did nt lter egg weights in the current study. Greter k incresed hert weights nd imprved crdic helth such tht pults gined mre weight the initil 3 dys f life. It my e cncluded tht the pult qulity ws imprved y the mternl diet y incresing eggshell cnductnce in lrge eggs. Cnclusins nd pplictins:. Feeding CCP t turkey dms imprved emry crdic helth cmpred t Cntrls.. The CCP dietry tretment ls incresed the grwth rte f htchling pults t 3 dys f ge cmpred t Cntrls. 3. Crdic helth f pults my e medited either y incresed functinl shell prperties r incresed free clcium ins. References Christensen, V.L., W.E. Dnldsn nd J.P. McMurtry, 996. Physilgicl differences in lte emrys frm turkey reeders t different ges. Pult. Sci., 75: 7-78. plsm T nd T cncentrtins. Int. J. Pult. Sci., 4 3 4: 68-73. Czrnecki, C.M. nd O.A. Evnsn, 980. Distriutin f mycrdil glycgen in turkey pults during develpment f furzlidne-induced crdimypthy. Pult Sci., 59: 50-54. Czrnecki, C.M., K. Renu nd E.F. Jnkus, 975. Bld glucse nd tissue glycgen levels in turkey pults nd spntneus rund hert disese nd furzlidne-induced crdimypthy. Avin Dis., 9: 773-780. Czrnecki, C.M., A. Jegers nd E.F. Jnkus, 978. Chrcteriztin f glycgen in selected tissues f turkey pults with spntneus rund hert disese nd furzlidne-induced crdimypthy. Act Ant., 0: 33-39. Dewr, W.A. nd W.G. Sillr, 97. Sdium txicity resulting frm feeding egg lumen pwder t turkey pults. Br. Pult. Sci., : 535-544. Firchild, B.D., V.L. Christensen, J.L. Grimes, M.J. Winelnd nd L.G. Bgley, 00. Hen ge reltinship with emrynic mrtlity nd fertility in cmmercil turkeys. J. Appl. Pult. Sci., : 60-65. Frme, D.D., D.M. Hge nd R. Cutler, 003. Interctive effects f dietry sdium nd chlride n the incidence f spntneus crdimypthy (rund hert) in turkeys. Pult. Sci., 80: 57-577. Gzdinski, P., T. Reidy, J.P. Villncurt nd R.J. Julin, 993. The reltin f egg specific grvity t the incidence f spntneus crdimypthy in tm turkeys. Avin Dis., 37: 993-000. Grimes, J.L., S. Nll, J. Brnnn, J.L. Gdwin, J.C. Smith nd R.D. Rwlnd, 004. Effect f chelted clcium prteinte dietry supplement n the reprductive perfrmnce f Lrge White Turkey Breeder Hens. J. Appl. Pult. Res., 3: 639-649. Hunsker, W.G., 97. Rund hert disese in fur cmmercil strins f turkeys. Pult. Sci., 50: 70-74. Jnkus, R.F., G.R. Nren nd N.A. Stley, 97. Furzlidne-induced crdic diltin in turkeys. Avin Dis., 6: 958-96. Mgwd, S.E. nd D.F. Bry, 96. Syndrme cnditin f turkey pults chrcterized y enlrged nd runded herts. Cn. J. Cmp. Med., 6: 68-7. Mirslimi, S.M., F.S. Qureshi, R.J. Julin nd P.J. O Brien, 990. Mycrdil ichemicl chnges in furzlidne induced crdimypthy in turkeys. J. Cmp. Pthl., 0: 39-47. 34
Christensen et l.: Emrynic Hert Onderk, D.K. nd R. Bhtngr, 98. Ultrstructurl chnges in sdium chlride-induced crdimypthy in turkey pults. Avin Dis., 6: 835-84. Rhn, H., 98. Gs exchnge in vin eggs with specil reference t turkey eggs. Pult. Sci., 60: 97-980. Rersn, K.D., 005. Inductin f rund hert disese in turkey pults y feed texture. Int. J. Pult. Sci., 4: 77-8. Rmnff, A.L. nd M. Schen, 938. Therml effect n the rte nd durtin f the emrynic hert rte f Gllus dmesticus. Ant. Rec., 65: 59-67. SAS Institute, 998. A User s Guide t SAS 98. Sprks Press, Inc., Cry, NC. Stley, N.A., G.R. Nren, C.M. Bndt nd H.L. Shrp, 978. Furzlidne-induced crdimypthy in turkeys. J. Pthl., 9: 53-544. Tullett, S.G., 98. Thereticl nd prcticl spects f eggshell prsity. Turkeys, 9: 4-8. The mentin f trde nmes in this pulictin des nt imply endrsement f the prducts mentined nr criticism f similr prducts nt mentined. Arevitin Key: CCP = cntining chelted clcium prteinte feed supplement; Cntrl = cntrl diet with n supplement; LDH = lctte dehydrgense; HI = Eggs were incuted t 39.0 C; C = Eggs were incuted t 37.5 C; G = eggshell cnductnce; k = eggshell cnductnce cnstnt. 343