Fulani Ecotype Chicken Genetic Resource under a Pastured Poultry Management System – 2 – Evaluation for Persistency of Egg Lay

Résumé

The objectives of this study were to describe egg-laying rate, evaluate the persistency of egg lay, and to characterise the laying patterns in Fulani ecotype hens (FEH) using non-linear models. Data on weekly egg production records of 83 laying hens up to 45 weeks of lay were used for this analysis. Four non-linear models including Gamma, Logistic-curvilinear, Compartmental, Narushin-Takma were fitted to describe the egg-laying rate, while the Grossman model was fitted to evaluate the persistency of egg lay. Goodness-of-fit criteria used included adjusted R² (adj. R² ), mean square error (MSE), and Akaike Information Criterion (AIC). The difference between the goodness-of-fit criterion (adj. R² ) was small for all models for egg laying rate. However, based on the AIC and R² values, Gamma and Narushin-Takma models presented the best fit. It was observed that the FEH could maintain constant egg production at weeks 9 to 11, and 39 to 41. In characterizing the laying patterns, FEH recorded double peaks at early and late laying periods. Overall, the data suggest that FEH are not persistent layers.