Genetic parameter estimates and response to selection for weight and testicular traits in Nelore cattle

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1 Gntic prmtr stimts n rspons to slction for wight n tsticulr trits in Nlor cttl F.R. Arujo Nto 1, R.B. Lôbo 2, M.D.S. Mot 3 n H.N. Olivir 1 1 Dprtmnto Gnétic Mlhormnto Animl, Fcul Ciêncis Agráris Vtrináris, Univrsi Estul Pulist Julio Msquit Filho, Jboticbl, SP, Brsil 2 Dprtmnto Gnétic, Fcul Micin Ribirão Prto, Univrsi São Pulo, Ribirão Prto, SP, Brsil 3 Dprtmnto Nutrição Mlhormnto Animl, Fcul Micin Vtrinári Zootcni, Univrsi Estul Pulist Julio Msquit Filho, Botuctu, SP, Brsil Corrsponing uthor: F.R. Arujo Nto E-mil: ntozoo@hotmil.com Gnt. Mol. Rs. 10 (4): (2011) Rciv Jnury 4, 2011 Accpt Jun 3, 2011 Publish Dcmbr 19, 2011 DOI ABSTRACT. W stimt gntic prmtrs for vrious phss of boy n tsticulr growth until 550 ys of g in Nlor cttl, using Bysin infrnc, incluing corrltion vlus n rror stimts. Wight n scrotl rcors of 54,182 Nlor nimls originting from 18 frms prticipting in th Brzilin Nlor Bring Progrm (PMGRN) wr inclu. Th following trits wr msur: wight t stnr gs of 120 (W120), 210 (W210), 365 (W365), 450 (W450), n 550 (W550) ys; wight gin btwn 120/210 (WG1), 210/365 (WG2), 365/450 (WG3), 450/550 (WG4), 120/365 (WG5), 120/450 (WG6), 120/550 (WG7), 210/450 (WG8), 210/550 (WG9), n 365/550 (WG10) Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

2 F.R. Arujo Nto t l ys of g; scrotl circumfrnc t 365 (SC365), 450 (SC450) n 550 (SC550) ys of g, n tsticulr growth btwn 365/450 (TG1), 450/550 (TG2) n 365/550 (TG3) ys of g. Th mol inclu contmporry group (currnt frm, yr n two-month prio of birth, sx, n mngmnt group) n g of m t clving, ivi into clsss s fix ffcts. Th mol lso inclu rnom ffcts for irct itiv, mtrnl itiv n mtrnl prmnnt nvironmntl, n rsiul ffcts. Th irct hritbility stimts rng from 0.23 to 0.39, 0.13 to 0.39 n 0.32 to 0.56 for wights t stnr gs, wight gins n tsticulr msurs, rspctivly. Th gntic corrltions btwn wights (0.69 to 0.94) n scrotl circumfrncs (0.91 to 0.97) msur t stnr gs wr highr thn thos btwn wight gin n tsticulr growth (0.18 to 0.97 n 0.36 to 0.77, rspctivly). Th wights t stnr gs rspon mor ffctivly to slction, n lso gv strong corrltions with th othr trits. Ky wors: Bf cttl; Gibbs smpls; Growth; Rprouctiv trits INTRODUCTION Th nw conomic orr, bs on comptition n constnt srch for prouctiv fficincy, hs forc livstock proucrs to opt nw tchnologis. Ths chngs in frm mngmnt r ccompni by gntic ltrtions of th hrs promot by th slction of nimls. This procss is support by th choic of critri comptibl with th objctiv of th ctivity n by th ccurt stimtion of (co)vrinc componnts of th trits slct. In bf cttl, wights n wight gins btwn crtin gs hv bn opt s slction critri bcus thy r sy to msur n intrprt, th possibility of promoting substntil gntic gin, n high gntic corrltions btwn ths msurs. In Brzil, gntic bring progrms inclu scrotl circumfrnc s rprouctiv critrion sinc, in ition to its sy msurmnt, this trit prsnts fvorbl gntic corrltions with prouctiv n rprouctiv trits in both fmls (Elr t l., 2004; Forni n Albuqurqu, 2005) n mls (Srriro t l., 2002; Kly t l., 2006). Th stimtion of (co)vrinc componnts for ny critri opt prmits th construction n ppliction of slction inics n of mix mol qutions, s wll s th clcultion of prmtrs such s hritbility n gntic corrltion, thus fcilitting th plnning of bring progrms n th intrprttion of gntic mchnisms involv in th xprssion of iffrnt trits (Hnrson, 1986). In viw of this importnc, vrious mthos of stimtion hv bn tst in quntittiv gntic nlyss to obtin ccurt stimts n to fcilitt th implmnttion of complx mols. In this rspct, Ginol n Frnno (1986) introuc th Bysin pproch in niml bring n Wng t l. (1993) subsquntly ppli it to linr mix mols using th Gibbs lgorithm. Th objctiv of th prsnt stuy ws to tst linr mix mols in combin nlyss by Bysin infrnc to stimt gntic prmtrs for iffrnt phss of boy n tsticulr growth until 550 ys of g in Nlor cttl, to contribut to slction progrms sign to improv ths trits. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

3 Gntic prmtrs for growth n rprouctiv trits 3129 MATERIAL AND METHODS Wight n scrotl rcors of Nlor nimls originting from 18 frms prticipting in th Brzilin Nlor Bring Progrm (PMGRN) wr us. Th following trits wr stui: wight t stnr gs of 120 (W120), 210 (W210), 365 (W365), 450 (W450), n 550 (W550) ys; wight gin btwn 120/210 (WG1), 210/365 (WG2), 365/450 (WG3), 450/550 (WG4), 120/365 (WG5), 120/450 (WG6), 120/550 (WG7), 210/450 (WG8), 210/550 (WG9), n 365/550 (WG10) ys of g; scrotl circumfrnc t 365 (SC365), 450 (SC450) n 550 (SC550) ys of g, n tsticulr growth btwn 365/450 (TG1), 450/550 (TG2) n 365/550 (TG3) ys of g. Explortory nlysis ws prform using th Sttisticl Anlysis Systm softwr (SAS Institut, 2003) to vlut th consistncy of th t. Th contmporry groups consist of currnt frm, yr n two-month prio of birth, sx, n mngmnt group. Rcors tht wr 3.5 stnr vitions bov or blow th mn of th group n contmporry groups contining progny from singl sir or fwr thn fiv nimls wr limint. Th fil contin t from 54,182 iniviuls (Tbl 1) n th numbr of nimls in th rltionship mtrix ws 82,692. Tbl 1. Summry of t structur n scriptiv sttistics for wight t stnr gs (W), wight gin (WG), scrotl circumfrnc (SC), n tsticulr growth (TG) in Nlor cttl. Trits N Mn SD Min. Mx. NS NM W120 (kg) 50, ,090 21,576 W210 (kg) 47, ,097 20,723 W365 (kg) 39, ,064 18,439 W450 (kg) 36, ,023 17,402 W550 (kg) 23, ,158 WG1 (kg) 45, ,061 19,936 WG2 (kg) 35, ,925 WG3 (kg) 31, ,805 WG4 (kg) 20, ,084 WG5 (kg) 37, ,008 17,795 WG6 (kg) 33, ,359 WG7 (kg) 21, ,152 WG8 (kg) 33, ,326 WG9 (kg) 21, ,112 WG10 (kg) 21, ,444 SC365 (cm) 12, ,665 SC450 (cm) 14, ,640 SC550 (cm) 7, ,013 TG1 (cm) 10, ,403 TG2 (cm) 6, ,216 TG3 (cm) 5, ,528 N = numbr of rcors; SD = stnr vition; NS = numbr of sirs; NM = numbr of mothrs. (Co)vrinc componnts wr stimt by multi-trit nlysis simultnously incluing th following trits: W120, SC365, WG1, WG2, WG3, WG4, TG1, n TG2. Th mol inclu contmporry group n g of m t clving ivi into clsss (for W120 n WG1) s fix ffcts. Th mol lso inclus rnom ffcts for irct itiv, mtrnl itiv (for W120 n WG1) n mtrnl prmnnt nvironmntl (for W120 n WG1), n rsiul. In viw of contrictory rsults in th litrtur, th covrinc btwn irct n mtrnl gntic ffcts ws fix t zro s on in othr stuis (Albuqurqu n Myr, 2001). Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

4 F.R. Arujo Nto t l Th GIBBS2F90 progrm (Misztl, 2007) ws us for nlysis. A chin of 1,131,500 cycls ws gnrt, with burn-in prio of 30,000 itrtions n smpling intrvl of 100. Gntic prmtrs for th othr chrctristics (W205, W365, W450, W550, WG5, WG6, WG7, WG8, WG9, WG10, SC450, SC550, n TG3) wr stimt through th sum of vrincs in ch vctor Th mtrix prsnttion of th complt mol us for nlysis is: (Eqution 1) whr y, β,, m, c, n r vctors of obsrvtions, fix ffcts, irct itiv gntic ffcts, mtrnl itiv gntic ffcts, mtrnl prmnnt nvironmntl ffcts, n rsiul ffcts, rspctivly, n X, Z 1, Z 2, n W r incinc mtrics tht rlt β,, m, n c to th obsrvtions. Uniform n Gussin priors wr ssum for fix n rnom ffcts, rspctivly: (Eqution 2) whr A, G, G m, E p, R, n I r th rltionship mtrics, irct gntic, mtrnl gntic, n mtrnl prmnnt nvironmntl n rsiul covrincs, n intity, rspctivly, n is th oprtor of th Kronckr prouct. For vrinc componnts, priors riv from invrs Wishrt istributions, corrsponing to th invrs chi-squr istribution in univrit css, wr us (Vn Tssll n Vn Vlck, 1996). Thus: (Eqution 3) whr S n v, S m n v m, S p n v p, n S r n v r r priori vlus n grs of from for irct itiv, mtrnl itiv, mtrnl prmnnt nvironmntl, n rsiul covrincs, rspctivly. Th burn-in prio n th smpling intrvl wr stblish mpiriclly n post- Gibbs nlysis ws prform using th Gibnl progrm (Vn Km, 1997) to trmin convrgnc n th numbr of ffctiv smpls. Th popultion prmtrs wr clcult in ch vctor, n th mn, min n mo of postrior istributions wr stimt. In ition, th 95% high-nsity intrvl (HDI) ws clcult sinc this prmtr is mor informtiv thn confinc intrvls in th cs of symmtric or multimol istributions (Hynmn, 1996). Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

5 Gntic prmtrs for growth n rprouctiv trits 3131 RESULTS AND DISCUSSION Anlysis of convrgnc, pnnc btwn smpls n rlibility of th stimts Th rsults obtin with th Gibnl progrm show tht th burn-in prio ws sufficint to trmin convrgnc of th chin. Th ffctiv smpl siz obtin for th prmtrs ws rltivly smll (22 to 1614) whn compr to th totl numbr of vctors gnrt. In gnrl, th corrltion stimts prsnt th grtst pnnc, with smllr ffctiv smpl siz bing ssocit with corrltions of mtrnl origin. Thrfor, th us of mol simultnously incluing lrg numbr of trits, lthough rprsnting mor xtnsiv sourc of informtion (Schffr, 1984), incrss th pnnc btwn smpls u to th numbr of prmtrs involv. In th cs of stimts rlt to mtrnl ffcts, th numbr of offspring pr m my hv incrs th pnnc btwn ths prmtrs, lthough othr fctors such s th numbr of ms with rcors lso intrfr with ths stimts (Hyrpour t l., 2008). Howvr, no minimum ffctiv smpl siz on which to infr hs bn rport in th litrtur. Th siz obtin in th prsnt stuy sm to b sufficint to obtin msurs of cntrl tnncy n vrition. With rspct to th rlibility of th stimts, hritbilitis n vrincs prsnt smll HDI n low stnr vition, finings inicting tht th prmtrs wr rlibl. Th corrltion stimts prsnt low stnr vitions, but xcptions wr obsrv. Gntic prmtr stimts n rspons to slction Th irct hritbility stimts for wights t stnr gs wr mort to high (0.23 to 0.39) n wr highr t olr gs (Tbl 2). Th mgnitu of vrition in ths stimts ws similr to tht rport by Albuqurqu n El Fro (2008), but th point stimts wr slightly highr. Th growing trn in th hritbility stimts, s lso monstrt by Albuqurqu n Myr (2001b) using rnom rgrssion, is u to th fct tht irct itiv vrinc incrss t highr rt thn rsiul vrinc with incrsing g s rsult of th combin ction of lrg numbr of gns on wights msur t th gs stui, whrs rnom nvironmntl ffcts tn to cncl ch othr ovr tim. With rspct to wight gins, th irct hritbility stimts rng from 0.13 to 0.39 n tn to b highr for wir intrvls (WG5 to WG9). Similr stimts hv bn rport in th litrtur. Pnto t l. (2002) obtin stimts rnging from 0.16 to 0.32 for totl gins btwn stnr gs. Krjcová t l. (2007), stuying ily wight gins ovr nin prios by multi-trit n rnom rgrssion nlysis, rport hritbilitis rnging from to Consiring th rsults prsnt, th slction bs on WG6 or WG7 ws foun to b s ffctiv s slction bs on wights t stnr gs, bcus substntil prt of th vrition ws u to th vrg ffct of gns. Howvr, it is importnt to consir th mgnitu of irct itiv vrinc, its rltionship with othr trits of intrst n oprtionl spcts, bcus it rquirs t lst two msurs in niml. With rspct to mtrnl ffcts, th hritbility stimts wr of low mgnitu n wr highr for wights t stnr gs (0.11 n 0.10 for W120 n W210, rspctivly) whn compr to wight gin (0.04 for WG1). Albuqurqu n Myr (2001b) rport highr mtrnl hritbilitis Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

6 F.R. Arujo Nto t l Tbl 2. Dscriptiv sttistics of postrior istribution for vrinc componnts n gntic prmtrs for wight t stnr g (W) n wight gins (WG). Trits Prmtrs Mn Mo Min SD ES HDI (95%) W120 σ σ σ m σ pm h h m c W210 σ σ σ m σ pm h h m c W365 σ σ , h W450 σ , σ , h W550 σ , σ , h , WG1 σ σ σ m σ pm h h m c WG2 σ σ h WG3 σ σ h WG4 σ σ h WG5 σ σ h WG6 σ σ , h WG7 σ , σ , h , WG8 σ σ , h WG9 σ σ h , WG10 σ σ h 2 σ 2 = irct itiv vrinc; σ2 = rsiul vrinc; σ2 m = mtrnl itiv vrinc; σ2 pm = mtrnl prmnnt nvironmntl vrinc; h 2 = irct hritbility; h2 m = mtrnl hritbility; c2 = mtrnl prmnnt nvironmntl vrinc componnt s proportion of phnotypic vrincs; ES = numbr of ffctiv smpls; SD = stnr vition; HDI = high-nsity intrvl. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

7 Gntic prmtrs for growth n rprouctiv trits 3133 for wights t 120 (0.25) n 240 (0.20) ys of g. In contrst to ths uthors who obsrv crs in th mtrnl ffct with g, in th prsnt stuy this ffct ws stbl t 120 n 210 ys. Thrfor, in viw of th similrity of mtrnl ffcts t ths gs n th highr phnotypic vrinc obsrv t 210 ys, grtr rspons to slction is xpct for mtrnl bility t this g. Rgring msurs of tsticulr growth, th hritbility stimts wr high (0.32 to 0.56), xcpt for TG2 (Tbl 3). As obsrv for th wight trits, grtr rspons to slction cn b chiv through slction bs on th scrotl circumfrnc t stnr gs. For trits obtin t stnr gs, th stimts wr highr thn thos rport by Yokoo t l. (2007) (0.48, 0.53 n 0.42 for SC365, SC450 n SC550, rspctivly). Similr stimts for TG1 n TG2 wr obsrv by Pnto t l. (2002) (0.24 n 0.18 for scrotl growth btwn 365/455 n 455/550 ys of g). Tbl 3. Dscriptiv sttistics of postrior istribution for vrinc componnts n gntic prmtrs for scrotl circumfrnc (SC) n tsticulr growth (TG). Trits Prmtrs Mn Mo Min SD ES HDI (95%) SC365 σ 2 σ 2 h 2 SC450 σ 2 σ 2 h 2 SC550 σ 2 σ 2 h 2 TG1 σ 2 σ 2 h 2 TG2 σ 2 σ 2 h 2 TG3 σ 2 σ 2 h σ 2 = irct itiv vrinc; σ2 = rsiul vrinc; h2 = irct hritbility; SD = stnr vition; ES = numbr of ffctiv smpls; HDI = high-nsity intrvl. Th gntic corrltions btwn wights (0.69 to 0.94) n scrotl circumfrncs (0.91 to 0.97) msur t stnr gs wr highr thn thos btwn wight gin n tsticulr growth (0.18 to 0.97 n 0.36 to 0.77, rspctivly) (Tbl 4). High corrltions for wight gin n tsticulr growth wr only obsrv btwn ovrlpping msurs. Similr rsults hv bn rport by Albuqurqu n Myr (2001b) for wights t stnr gs using rnom rgrssion mols n by Yokoo t l. (2007) btwn msurs of scrotl circumfrnc t 365, 450 n 550 ys of g. Th gntic corrltions obtin for wight gins show mgnitu similr to tht rport by Krjcová t l. (2007), xcpt for som ngtiv corrltions ( to 0.958). For trits msur t stnr gs (wight n scrotl circumfrnc), n invrs rltionship ws obsrv btwn th gntic corrltion stimt n chronologicl istnc btwn th two msurs. Similr rsults hv bn rport by Albuqurqu n Myr (2001b) using rnom rgrssion mols for wights. Wight gins prsnt highr corrltions with wights just for g t th uppr limit of th intrvl tht trmin th wight gin. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

8 F.R. Arujo Nto t l Tbl 4. Estimts of postriori vrg n stnr vition (in prnthss) of th gntic (top right) n nvironmntl (bottom lft) corrltions btwn th chrctristics of wight n tsticulr vlopmnt [scrotl circumfrnc (SC) n tsticulr growth (TG)] in th Nlor cttl. W120 W210 W365 W450 W550 WG1 WG2 WG3 WG4 WG5 WG6 W (0.01) 0.78 (0.02) 0.73 (0.02) 0.69 (0.02) 0.55 (0.04) 0.12 (0.05) 0.24 (0.05) 0.29 (0.06) 0.35 (0.04) 0.36 (0.04) W (0.00) (0.01) 0.82 (0.01) 0.80 (0.02) 0.81 (0.02) 0.24 (0.05) 0.25 (0.05) 0.42 (0.05) 0.56 (0.03) 0.53 (0.03) W (0.01) 0.70 (0.01) (0.00) 0.94 (0.01) 0.80 (0.02) 0.66 (0.03) 0.43 (0.05) 0.47 (0.05) 0.86 (0.01) 0.83 (0.02) W (0.01) 0.61 (0.01) 0.85 (0.00) (0.00) 0.73 (0.03) 0.70 (0.02) 0.63 (0.04) 0.48 (0.06) 0.86 (0.01) 0.90 (0.01) W (0.01) 0.59 (0.01) 0.73 (0.01) 0.85 (0.00) (0.03) 0.67 (0.03) 0.60 (0.04) 0.68 (0.04) 0.85 (0.01) 0.88 (0.01) WG (0.01) 0.69 (0.01) 0.47 (0.01) 0.39 (0.01) 0.39 (0.01) (0.05) 0.18 (0.06) 0.52 (0.06) 0.74 (0.02) 0.65 (0.03) WG (0.01) (0.01) (0.01) (0.01) 0.33 (0.01) (0.01) (0.05) 0.31 (0.06) 0.89 (0.01) 0.88 (0.01) WG (0.00) (0.01) (0.01) 0.47 (0.01) 0.37 (0.01) (0.01) (0.01) (0.07) 0.44 (0.05) 0.71 (0.03) WG (0.01) 0.11 (0.01) (0.01) (0.01) 0.48 (0.01) 0.09 (0.01) (0.01) (0.01) (0.05) 0.47 (0.05) WG (0.01) 0.25 (0.01) 0.79 (0.01) 0.65 (0.01) 0.53 (0.01) 0.48 (0.01) 0.80 (0.00) (0.01) (0.01) (0.01) WG (0.01) 0.20 (0.01) 0.62 (0.01) 0.84 (0.00) 0.67 (0.01) 0.37 (0.01) 0.63 (0.01) 0.54 (0.01) (0.01) 0.79 (0.00) - WG (0.01) 0.24 (0.01) 0.53 (0.01) 0.69 (0.01) 0.88 (0.01) 0.38 (0.01) 0.45 (0.01) 0.41 (0.01) 0.52 (0.01) 0.63 (0.01) 0.79 (0.01) WG (0.01) (0.01) 0.41 (0.01) 0.68 (0.01) 0.50 (0.01) (0.01) 0.75 (0.00) 0.60 (0.01) (0.01) 0.58 (0.01) 0.86 (0.00) WG (0.01) (0.01) 0.34 (0.01) 0.55 (0.01) 0.76 (0.01) (0.01) 0.56 (0.01) 0.47 (0.01) 0.51 (0.01) 0.45 (0.01) 0.67 (0.01) WG (0.01) 0.07 (0.01) (0.01) 0.27 (0.01) 0.63 (0.01) 0.04 (0.01) (0.01) 0.62 (0.01) 0.73 (0.01) (0.01) 0.28 (0.01) SC (0.02) 0.39 (0.02) 0.52 (0.02) 0.49 (0.02) 0.44 (0.02) 0.27 (0.02) 0.26 (0.02) 0.06 (0.02) 0.02 (0.02) 0.40 (0.02) 0.37 (0.02) SC (0.02) 0.36 (0.02) 0.48 (0.02) 0.53 (0.02) 0.52 (0.02) 0.25 (0.02) 0.24 (0.02) 0.20 (0.02) 0.09 (0.03) 0.36 (0.02) 0.44 (0.02) SC (0.02) 0.38 (0.03) 0.46 (0.03) 0.50 (0.02) 0.57 (0.03) 0.26 (0.02) 0.20 (0.02) 0.18 (0.02) 0.25 (0.03) 0.33 (0.02) 0.39 (0.03) TG (0.02) 0.09 (0.02) 0.13 (0.02) 0.25 (0.02) 0.28 (0.02) 0.06 (0.02) 0.07 (0.02) 0.26 (0.02) 0.12 (0.02) 0.09 (0.02) 0.24 (0.02) TG (0.02) 0.10 (0.02) 0.07 (0.02) 0.06 (0.02) 0.20 (0.02) 0.06 (0.02) (0.02) (0.02) 0.27 (0.02) 0.02 (0.02) 0.02 (0.02) TG (0.02) 0.13 (0.02) 0.14 (0.02) 0.21 (0.02) 0.33 (0.02) 0.09 (0.02) 0.03 (0.02) 0.17 (0.02) 0.28 (0.02) 0.08 (0.02) 0.17 (0.02) Continu on nxt pg Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

9 Gntic prmtrs for growth n rprouctiv trits 3135 Tbl 4. Continu. WG7 WG8 WG9 WG10 SC365 SC450 SC550 TG1 TG2 TG3 W (0.04) 0.19 (0.04) 0.27 (0.04) 0.34 (0.05) 0.49 (0.04) 0.41 (0.04) 0.40 (0.04) 0.16 (0.06) 0.13 (0.09) 0.18 (0.06) W (0.03) 0.27 (0.04) 0.39 (0.04) 0.43 (0.04) 0.56 (0.03) 0.49 (0.04) 0.48 (0.04) 0.24 (0.06) 0.17 (0.09) 0.25 (0.06) W (0.02) 0.66 (0.03) 0.71 (0.03) 0.57 (0.04) 0.53 (0.03) 0.49 (0.03) 0.49 (0.04) 0.28 (0.05) 0.24 (0.08) 0.32 (0.06) W (0.01) 0.77 (0.02) 0.80 (0.02) 0.68 (0.04) 0.44 (0.03) 0.41 (0.03) 0.42 (0.04) 0.25 (0.05) 0.22 (0.09) 0.28 (0.06) W (0.01) 0.74 (0.02) 0.86 (0.01) 0.81 (0.02) 0.42 (0.04) 0.38 (0.04) 0.41 (0.04) 0.22 (0.05) 0.26 (0.08) 0.29 (0.06) WG (0.03) 0.33 (0.05) 0.48 (0.05) 0.46 (0.05) 0.50 (0.04) 0.48 (0.04) 0.47 (0.05) 0.31 (0.06) 0.16 (0.10) 0.30 (0.07) WG (0.02) 0.92 (0.01) 0.84 (0.02) 0.49 (0.05) 0.22 (0.05) 0.23 (0.04) 0.26 (0.05) 0.19 (0.06) 0.24 (0.09) 0.26 (0.07) WG (0.04) 0.79 (0.03) 0.73 (0.03) 0.74 (0.03) (0.05) (0.05) (0.06) 0.04 (0.07) 0.02 (0.11) 0.02 (0.09) WG (0.03) 0.34 (0.06) 0.69 (0.03) 0.84 (0.02) 0.18 (0.06) 0.15 (0.06) 0.21 (0.06) 0.05 (0.07) 0.32 (0.10) 0.20 (0.07) WG (0.01) 0.82 (0.02) 0.84 (0.02) 0.58 (0.05) 0.40 (0.04) 0.39 (0.04) 0.41 (0.04) 0.29 (0.05) 0.25 (0.08) 0.33 (0.06) WG (0.01) 0.93 (0.01) 0.92 (0.01) 0.72 (0.03) 0.29 (0.04) 0.30 (0.04) 0.32 (0.04) 0.24 (0.05) 0.20 (0.09) 0.27 (0.06) WG (0.01) 0.97 (0.00) 0.86 (0.02) 0.29 (0.04) 0.29 (0.04) 0.32 (0.04) 0.20 (0.05) 0.27 (0.08) 0.28 (0.06) WG (0.01) (0.01) 0.68 (0.03) 0.12 (0.04) 0.14 (0.04) 0.17 (0.05) 0.16 (0.06) 0.17 (0.08) 0.20 (0.06) WG (0.00) 0.76 (0.01) (0.01) 0.17 (0.04) 0.18 (0.04) 0.22 (0.04) 0.14 (0.05) 0.27 (0.08) 0.24 (0.06) WG (0.01) 0.27 (0.01) 0.72 (0.01) (0.05) 0.09 (0.05) 0.13 (0.05) 0.06 (0.06) 0.22 (0.09) 0.16 (0.07) SC (0.02) 0.25 (0.02) 0.23 (0.02) 0.06 (0.02) (0.01) 0.91 (0.01) 0.63 (0.05) 0.26 (0.08) 0.57 (0.05) SC (0.03) 0.33 (0.02) 0.34 (0.03) 0.21 (0.02) 0.78 (0.01) (0.01) 0.83 (0.02) 0.32 (0.08) 0.74 (0.04) SC (0.03) 0.28 (0.02) 0.41 (0.03) 0.31 (0.02) 0.58 (0.02) 0.80 (0.01) (0.03) 0.54 (0.07) 0.85 (0.02) TG (0.02) 0.22 (0.02) 0.27 (0.02) 0.27 (0.02) 0.02 (0.03) 0.64 (0.02) 0.56 (0.03) (0.09) 0.87 (0.03) TG (0.02) (0.02) 0.17 (0.02) 0.21 (0.02) (0.04) (0.04) 0.49 (0.03) 0.01 (0.03) (0.05) TG (0.02) 0.14 (0.02) 0.30 (0.02) 0.33 (0.02) (0.04) 0.32 (0.03) 0.74 (0.02) 0.67 (0.02) 0.75 (0.01) - W = wight t stnr g; WG = wight gin. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

10 F.R. Arujo Nto t l Th highst rsiul corrltions (Tbl 4) wr obsrv btwn trits msur t stnr gs, whrs th mgnitu of rsiul corrltions btwn msurs of wight gin n tsticulr growth ws low n ngtiv corrltions wr frquntly obsrv btwn subsqunt msurmnts. Ngtiv n low rsiul corrltions wr lso obsrv btwn wight gin n wights n btwn tsticulr growth n msurs of scrotl circumfrnc. This fining inicts tht nvironmnts fvoring som trits cn b unfvorbl for othrs. Ths ngtiv n low rsiul corrltions spcilly btwn chronologiclly clos msurs suggst tht climtic chngs tht occur uring th yr r th min fctors rsponsibl, lthough th contmporry groups inclu this ffct. With rspct to wight n scrotl circumfrnc, th highst rsiul corrltion ws obsrv btwn jcnt msurs, i.., th mor istnt th two msurmnts, th mor istinct th nvironmntl conitions n th non-itiv gntic ffcts tht influnc thm. Anlyzing th corrltions btwn wight gins n wights t stnr gs, th highst corrltion ws foun btwn wight gin n wight msur t its uppr limit, s obsrv for gntic corrltions. Th highr hritbilitis for wight n scrotl circumfrnc msur t stnr gs whn compr to wight gin n scrotl growth lso sm to b th rsult of th lowr rsiul corrltions compr to gntic corrltions btwn gins. This fct lso xplins th incrs of hritbilitis for wight n scrotl circumfrnc with incrsing g of th nimls. Sinc wight n scrotl circumfrnc msur t stnr gs r normlly us in Brzil s th min slction critri for Nlor cttl, th rspons to slction of ths trits ws vlut using iffrnt critri tht coul b opt (Figurs 1 n 2). Th us of wights t stnr gs s slction critri show tht, xcpt for W210, irct slction is th most ffctiv pproch to incrs wight t crtin g. Slction for wight t crtin g shows similr fficincy to incrs wights t prvious gs s irct slction for ths trits. WG1, WG6 n WG7 wr foun to b th most ffctiv slction critri mong th wight gin trits. Among th tsticulr trits, SC365 ws th most ffctiv slction critrion to incrs wights in th nxt gnrtion. Whn th objctiv ws to incrs scrotl circumfrnc t iffrnt gs, th bst slction critri wr W365 n WG5 mong wight trits n TG1 mong tsticulr trits sinc ths trits show th highst incrss irrspctiv of g. With rspct to scrotl circumfrnc t stnr g, SC450 ws foun to b n ttrctiv critrion sinc th gins obtin by inirct slction t othr gs wr similr to thos obtin by irct slction. Consirtions rgring th choic of slction critri for Nlor cttl First, wights t stnr gs r th bst critri sinc thy rspon mor ffctivly to slction, proviing lso substntil inirct gins in othr trits. W550 ws foun to b th most ffctiv slction critrion mong th wight trits stui. Howvr, th choic of th slction critrion shoul tk into ccount th importnc of th trits for th brr n th cost of mintnnc of th nimls until th g of rcoring. Th stimt gntic corrltions btwn wight gin n wight t stnr g suggst th ltrntiv us of th formr s slction critrion sinc thy provok smllr incrs in birth wight n mtur wight. In ition, othr stuis hv monstrt fvorbl ssocitions btwn ths msurs n othr trits of conomic intrst (Arthur t l., 2001). Furthr stuis invstigting wight gin s slction critrion for Nlor cttl r ncssry. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

11 Gntic prmtrs for growth n rprouctiv trits 3137 Figur 1. Expct rspons to slction for wights t stnr gs, whn th slction is on through: A. wights t stnr gs (W, in kg), B. wight gin (WG, in kg), n C. scrotl circumfrnc (SC) n tsticulr growth (TG), both in cm. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

12 F.R. Arujo Nto t l Figur 2. Expct rspons to slction for scrotl circumfrnc, whn th slction is on through: A. wights t stnr gs (W, in kg), B. wight gin (WG, in kg), n C. scrotl circumfrnc (SC) n tsticulr growth (TG), both in cm. Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

13 Gntic prmtrs for growth n rprouctiv trits 3139 With rspct to tsticulr trits, SC365 ws foun to b th bst slction critrion sinc its hritbility ws similr to tht of SC450 n SC550, in ition to prsnting highr gntic corrltion with wights t stnr gs. In this rspct, th fct tht this trit mnifsts t youngr g prmits ruction in th gnrtion intrvl. Accoring to Toll n Robison (1985), rly tsticulr trits r rflx of boy vlopmnt, whrs lt trits r influnc by th hormonl systm. This sttmnt is support by th highr gntic corrltions btwn wights n SC365 obsrv in this stuy, with highr tsticulr ctivity bing obsrv ftr this g in Zbu nimls. As consqunc, msurs obtin ftr 365 ys of g my prsnt highr corrltion with fml rprouctiv trits. ACKNOWLEDGMENTS W thnk th Ntionl Assocition of Cttl Brrs n Rsrchrs (ANCP) for proviing ccss to th tbs. Rsrch support by CAPES. REFERENCES Albuqurqu LG n Myr K (2001). Estimts of irct n mtrnl gntic ffcts for wights from birth to 600 ys of g in Nlor cttl. J. Anim. Br. Gnt. 118: Albuqurqu LG n Myr K (2001b). Estimts of covrinc functions for growth from birth to 630 ys of g in Nlor cttl. J. Anim. Sci. 79: Albuqurqu LG n El Fro L (2008). Comprçõs ntr os vlors gnéticos pr crctrístics crscimnto bovinos rç Nlor pritos com molos imnsão finit ou infinit. Rv. Brs. Zootc. 37: Arthur PF, Rnn G n Kruss D (2001). Gntic n phnotypic rltionships mong iffrnt msurs of growth n f fficincy in young Chrolis bulls. Livst. Pro. Sci. 68: Elr JP, Silv JA, Evns JL, Frrz JB, t l. (2004). Aitiv gntic rltionships btwn hifr prgnncy n scrotl circumfrnc in Nllor cttl. J. Anim. Sci. 82: Forni S n Albuqurqu LG (2005). Estimts of gntic corrltions btwn ys to clving n rprouctiv n wight trits in Nlor cttl. J. Anim. Sci. 83: Ginol D n Frnno RL (1986). Bysin mthos in niml bring thory. J. Anim. Sci. 63: Hnrson CR (1986). Rcnt vlopmnts in vrinc n covrinc stimtion. J. Anim. Sci. 63: Hyrpour M, Schffr LR n Yzi MH (2008). Influnc of popultion structur on stimts of irct n mtrnl prmtrs. J. Anim. Br. Gnt. 125: Hynmn RJ (1996). Computing n grphing highst nsity rgions. Am. Stt. 50: Kly CG, McNil MD, Tss MW, Gry TW, t l. (2006). Gntic prmtr stimts for scrotl circumfrnc n smn chrctristics of Lin 1 Hrfor bulls. J. Anim. Sci. 84: Krjcová H, Milnz N, Pribyl J n Schülr L (2007). Estimtion of gntic prmtrs for ily gins of bulls with multitrit n rnom rgrssion mols. Arch. Tirzucht. 50: Misztl I (2007). BLUPF90 fmily of progrms. Avilbl t [ Accss Mrch 12, Pnto JCC, Lmos DC, Bzrr LAF, Mrtins Filho R, t l. (2002). Estuo crctrístics quntittivs crscimnto os 120 os 550 is i m go Nlor. Rv. Brs. Zootc. 31: Srriro LC, Brgmnn JAG, Quirino CR, Pin NR, t l. (2002). Hrbili corrlção gnétic ntr prímtro scrotl, libio crctrístics sminis touros Nlor. Arq. Brs. M. Vt. Zootc. 54: SAS Institut (2003). SAS - Sttisticl Anlysis Systm. Usr s Gui, Cry. Schffr LR (1984). Sir n cow vlution unr multipl trit mols. J. Diry Sci. 67: Toll VD n Robison OW (1985). Estimts of gntic corrltions btwn tsticulr msurmnts n fml rprouctiv trits in cttl. J. Anim. Sci. 60: Vn Km JBCHM (1997). Gibnl: Anlyzing Progrm for Mrkov Chin Mont Crlo Squncs, Vrsion 2.4. Dpt. Anim. Sci., Wgningn Agric. Univ., Wgningn. Vn Tssll CP n Vn Vlck LD (1996). Multipl-trit Gibbs Smplr for niml mols: flxibl progrms for bysin n liklihoo-bs (co)vrinc componnt infrnc. J. Anim. Sci. 74: Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP

14 F.R. Arujo Nto t l Wng CS, Rutlg JJ n Ginol D (1993). Mrginl infrncs bout vrinc componnts in mix linr mol using Gibbs smpling. Gnt. Sl. Evol. 25: Yokoo MJI, Albuqurqu LG, Lôbo RB, Sinz RD, t l. (2007). Estimtivs prâmtros gnéticos pr ltur o postrior, pso circunfrênci scrotl m bovinos rç Nlor. Rv. Brs. Zootc. 36: Gntics n Molculr Rsrch 10 (4): (2011) FUNPEC-RP