Periódicos Brasileiros em Medicina Veterinária e Zootecnia

p. 846-853

Estimates of genetic parameters of growth traits of Nellore cattle in the Midwest region of Brazil

Araújo, Cláudio Vieira deLôbo, Raysildo BarbosaFigueiredo, Luis Gustavo GirardiMousquer, Cláudio JonassonLaureano, Monyka Marianna MassoloniBittencourt, Thereza Cristina Borio dos Santos Calmon deAraújo, Simone Inoe

Records of birth weight (BW) and weights standardized to 210 (W210); 365 (W365) and 550 (W550) of age in the Nellore breed were used to estimate variance components of genetic effects and predict genetic values of sires. The model included the fixed effects of contemporary group and cow age at calving as co-variable, and the additive and maternal genetic, permanent maternal environmental, and temporary environmental random effects. Estimates of means and standard deviations for BW, W210; W365 and W550 were 32.76 ± 3.74; 184.30 ± 29.02; 240.31 ± 41.85 and 322.12 ± 60.77, respectively. A significant additive genetic variability was detected for all weights. The permanent maternal environmental variance showed greater relevance on weaning weight, and it was practically inexistent after weaning. For the maternal genetic variance, the estimate for birth weight was more significant as compared with weaning weight. The estimated heritability values for BW, W210; W365 and W550 were 0.37 ± 0.02; 0.36 ± 0.03; 031 ± 0.01 and 0.38 ± 0.02, respectively. Genetic correlations between birth weight and other weights were of low magnitude, with high values of weights at other ages.(AU)

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