Produção Nacional
Growth curves on females of the Caracu breed
2016; UNIVERSIDADE ESTADUAL DE LONDRINA; Volume: 37; Issue: 4Supl1 Linguagem: Inglês
10.5433/1679-0359.2016v37n4supl1p2749
ISSN1679-0359
AutoresRaphael Patrick Moreira, Maria Eugênia Zerlotti Mercadante, Victor Breno Pedrosa, Joslaine Noely dos Santos Gonçalves Cyrillo, Wignez Henrique,
Tópico(s)Genetics and Plant Breeding
ResumoThe objective of the study was to analyze nonlinear models that best fit the growth of Caracu cows. The experiment was conducted at the Instituto de Zootecnia, Centro APTA Bovinos de Corte, Sertãozinho, SP. Data of weight at birth to 63 months of age, from 500 females of the Caracu breed were used. The mean weight at birth (BW), weaning weight (W7), weight at 26 months (W26) and weight at 63 months (W63) were, respectively, 32 kg, 198 kg, 354 kg and 488 kg, providing an average daily gain (ADG) of 0.241 kg/day. The nonlinear models used were: Brody, Von Bertalanffy, Logistic and Gompertz. All of the models tended to describe accordingly the growth curve of these animals, but, according to the mean square residual and coefficient of determination adopted to select the most appropriate model, Brody showed the best fit. All models presented a high and negative correlation between the A and k parameters, indicating that the most precocious animals are less likely to reach elevated weights at 63 months of age. The effect of year of birth significantly affected (P < 0.01) the parameters A and k, concluding that the animal selection based on growth traits favored the increase of mature weight and growth precocity over the generations.
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