Souz J.C.,Federal University of Mato Grosso do Sul |
Vaz K.M.,Federal University of Mato Grosso do Sul |
Silva R.M.,Federal University of Mato Grosso do Sul |
Mota M.F.,University Federal da Fronteira Sul |
And 4 more authors.
Livestock Research for Rural Development | Year: 2014
The objectives of this study were to determine genetic and environmental effects on weight at 205 days of age (P205), at 365 days (P365) and at 550 days (P550), to determine the effect of bulls within farm; and to analyze the effects of the phases of the moon on the incidence of the parturition. The statistical model included the fixed effects of sex, birth season (dry and wet), year of birth of the calf, and the random effects of sire within farm and the error. Genetic parameters were obtained by uni-character analysis, considering the fixed effect of contemporary groups and the random effects of the direct and maternal additive effects, beyond the effect of uncorrelated dam permanent environment. All sources of variation were significant (P <0.05), except for the effect of season of birth weight at 550 days of age. Estimates of direct and maternal heritability were 0.42±0.08 and 0.18±0.06; 0.51±0.11 and 0.29±0.11; 0.58±0.15 and 0.11±0.14 for P205, P365 and P550, respectively. The direct heritability estimates indicate the possibility of obtaining higher genetic gains through selection. The effects of non-genetic influence on live weight gain, stress the need to make adjustments for them. The moon effect was significant for the incidence of parturition, with the greatest incidence in the transition to full moon.