Resumen

SIMANCA, Juan C; VERGARA, Oscar D  y  BUSTAMANTE, Moris de J. Description of Growth in Sheep Santa Ines x Creole in Extensive Grazing in Two Populations from Cordoba, Colombia. Rev. Fac. Cienc. Vet. [online]. 2016, vol.57, n.1, pp.61-67. ISSN 0258-6576.

With the objective to verify which was the model that best describes the growth of sheep Santa Ines x Creole in two sheep populations in the department of Cordoba, Colombia, and determine the effect of sex and farm on the estimated parameters, models of Brody, Logistic models Gompertz and Von Bertalanffy were evaluated. In addition, the percentage of maturity at 4 to 6 months, and age at 75 and 95% maturity was estimated for the model that best described the growth curve. Weighing 77 sheep born between the months of November 2013 and April 2014 were used. The parameters were estimated using the procedure NLIN of SAS. To verify that curve would be adequate to describe the growth of the populations studied Aikaike Information Criterion, the Bayesian Information Criterion, the Coefficient of Determination and Percentage of Curves Converged were considered. Von Bertalanffy model was presented better fit. For this model, sex effect was not significant for any of the estimated parameters. The farm effect was significant for all the estimated parameters. Von Bertalanffy model showed a better adjustment. For this model, sex effect was not significant (P>0.05) for any of the estimated parameters. The farm effect was highly significant (P≤0.05) for all the estimated parameters. The estimates for β₀, β₁ and β₂ were 41.21, 0.5896 and 0.0075, respectively. The percentage of maturity at four months was 42.25% and 56.12% at six; age at 75% and 95% of maturity were 310 and 589 d, respectively. According to the estimated percentage of maturity and age at maturity, in sheep populations studied should improve the nutritional management and food of the animals, in order that they achieve maturity at a younger age.

Palabras clave : Sheep; growth; multipurpose breeds; statistical methods; age of maturity; weight; Córdoba.

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