Estimates of generic parameters and phenotypic, genetic and environmental trends of some reproductive traits in Gir cattle

被引:4
作者
Balieiro, ES [1 ]
Pereira, JCC
Verneque, RS
Pereira, CS
Bergmann, JAG
机构
[1] UNFRRJ, Inst Zootecn, BR-23851970 Seropedica, RJ, Brazil
[2] Univ Fed Minas Gerais, Escola Vet, Belo Horizonte, MG, Brazil
[3] CNPGL Embrapa, Sao Paulo, Brazil
关键词
cattle; dairy Gyr; genetic parameters; phenotypic trend; genetic trend;
D O I
10.1590/S0102-09351999000400014
中图分类号
S85 [动物医学(兽医学)];
学科分类号
0906 ;
摘要
The aims of the present study were to estimate genetic parameters, as well as phenotypic, genetic and environmental trends for age at first calving (AFC) and calving intervals (CI) on Gyr dairy breed, using a multivariate derivative-free restricted maximum likelihood (MTDFREML) with an animal model. The mathematic model for calving interval included herd-year of calving, calving season, and the covariate age of cow as fixed effects, and animal, and permanent environment as random effects. The model for age at first calving included herd-year of birth and season of birth as fixed effects, and animal as random effect. Through the bivariate analyses, estimates of heritability were: for age at first calving 0.17 and for calving interval 0.06. The estimate of repeatability for calving interval was 0.17. The phenotypic, genetic and environmental correlations between age at first calving and calving interval were 0.06, 0.37 and 0.03, respectively. The phenotypic, genetic and environment annual trends for age at first calving rc-ere, respectively, -0.446+/-0,077 (P<0.01), 0.008+/-.013 and -0.454 months based on breeding values of cows, and -0.185+/-0.083 (P<0.05), 0.051+/-0.059 and -0.236 months based on breeding values of bulls. The phenotypic, generic and environment annual trends for calving interval were, respectively, -1.25+/-0.95, -0.98+/-0.19(P<0.01) and -0,27 days based on breeding values of cows, and -0.88+/-1.07, -1.62+/-0.40 (P<0.01) and 0,74 days based on breeding values of bulls.
引用
收藏
页码:371 / 376
页数:6
相关论文
共 27 条
[21]   POSTPARTUM PERFORMANCE OF DAIRY HEIFERS FRESHENING AT YOUNG AGES [J].
SIMERL, NA ;
WILCOX, CJ ;
THATCHER, WW .
JOURNAL OF DAIRY SCIENCE, 1992, 75 (02) :590-595
[22]  
SOUZA EM, 1991, REUN AN SOC BRAS ZOO, V28, P582
[23]  
SOUZA EM, 1991, REUN AN SOC BRAS ZOO, V28, P580
[24]  
Teixeira Nilson Milagres, 1994, Revista da Sociedade Brasileira de Zootecnia, V23, P992
[25]  
VERNEQUE RS, 1982, THESIS UFV VICOSA
[26]  
WINKLER R, 1993, C BRAS PESQ EM ZEB 1, V2, P58
[27]  
ZAMBIANCHI AR, 1996, THESIS UNESP JABOTIC