Characterisation of biological growth curves of different varieties of an endangered native hen breed kept under free range conditions

The aim of this study is to model the growth samples four varieties (White, Black, Partridge, Franciscan) Spanish Utrerana hen breed, which endangered, by using Brody, Von Bertalanffy, Verhulst, Logistic and Gompertz models. For purpose, a total 16,235 weight data observations from 2004 animals reared in free range system were collected. was best suited for predicting biological curve White variety both sexes, while Bertalanffy fitting rest individuals based on 5 goodness-of-fit flexibility criteria: Pseudo-R2, mean squared error, Akaike information criterion, Bayesian criterion coherence estimated parameters. Black heaviest, with values 2605.96 2032.61 g (for males females, respectively) parameter, presented lowest maturity (a = 2442.99 1874.24 g, respectively). Conclusively, characterisation essential conservation hen, search new market niches greater profitability differentiated product.HighlightsNon-linear models can explain growth.Females reach earlier than males.Utrerana shows strong sexual dimorphism.