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Artigo Produção Nacional Revisado por pares
BIBTEX RIS

Long-term growth of body, body parts and composition of gain of dairy goat wethers

2015; Cambridge University Press; Volume: 153; Issue: 7 Linguagem: Inglês

10.1017/s0021859615000532

ISSN

1469-5146

Autores

Raphael Pavesi Araújo, Ricardo Augusto Mendonça Vieira, Norberto Silva Rocha, Matheus Lima Corrêa Abreu, Leonardo Siqueira Glória, N.M. Rohem Júnior, Alberto Magno Fernandes,

Tópico(s)

Reproductive Physiology in Livestock

Resumo

SUMMARY The goal of the present study was to characterize the growth of body parts and composition of the growing empty body to infer how these aspects relate to the long-term growth of goat wethers from dairy breeds. Animals were slaughtered at several ages from birth to maturity (≅900 days old). All body parts were weighed and sampled to determine chemical constituent dry matter, crude protein, crude fat, ash and specific energy. The monomolecular (Brody), Gompertz, and Richards models, a biphasic model formed by the combined Brody and Gompertz functions, and a simple linear model were fitted to the growth profiles with different variance functions and were all evaluated using likelihood-information criteria. The effect of breed (genotype) was accounted for in all models but the resulting models were not more likely than the models without the breed effect. Remarkable differences were observed regarding inflection points, growth rates and trends for all body parts and chemical constituents of the body. The biphasic model did not supplant the monomolecular, Gompertz, Richards or the linear model in terms of likelihood-information criteria. Therefore, body parts and chemical constituents of the empty body presented monomolecular, sigmoid and linear time-trends. The growth profiles of fat, protein and energy of the empty body did not scale isometrically with the empty body proper. In addition, the variance was heteroscedastic along the time scale and was better represented by both an exponential variance over time or by a power function of the mean.

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