Growth curve of Repartida goats reared in the Caatinga region, Brazil

• Autor(a) principal: Pires, Luanna Chácara
• Data de Publicação: 2017
• Outros Autores: Machado, Théa Mírian Medeiros, Carneiro, Paulo Luiz Souza, Silva, João Batista Lopes da, Barbosa, Andréa Duarte de Holanda, Torres, Robledo de Almeida
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/26297
• topic: Body weight; Growth rate; Naturalized goats; Brazil Caatinga.; Peso corporal; Taxa de crescimento; Caprinos naturalizados; Caatinga.

This work aimed to determine which non-linear model (Brody, Gompertz, logistic, von Bertalanffy or Richards) best represents the average growth curve of goats, in addition to evaluating the effect of the environment. The weight data of 40 Repartida goats reared in the Brazil Caatinga were included in this study. Weight data was collected every 30 days from birth until 270 days of age. The parameters of the models (A, mature body weight; B, constant of integration; k, maturation rate; m, inflection point) were estimated using the NLIN procedure of SAS. The logistic model showed a slightly higher average fit in comparison to the other models. The absolute growth rate suggests that the maximum growth rate was reached early. The effect of the contemporary groups was significant (P < 0.05), but only for the estimated k parameter. The estimated correlation between the A and k parameters was significant and negative, indicating a lower probability of a high body weight in adulthood. Goats of the Repartida ecotype are characterized by their high birth weight and low weight at maturity, which combined with the nutritional deficit, suggests that these animals have adapted to the adverse conditions of the Brazilian Caatinga region.