Shape of curve lactation affects the fitting of empirical and mechanistic models applied to dairy sheep lactations in Mexico

The ability of mathematical models to represent the lactation process varies according with their mathematical structure and database characteristics. The aim of the current study was evaluated the goodness of fit of empirical and mechanistic models applied to dairy sheep lactation curves with different shapes. A total of 4,494 weekly test day records were analyzed. All lactations were individually fitted using two empirical (Wood and Wilmink) and two mechanistic (Dijkstra, and Pollott) models. The Dijkstra model showed the best performance to typical curves and Wood model to atypical curves (without peak lactation). Therefore, the selection of the mathematical model to fit sheep lactation curves must consider the specific patter of milk production.