Dutch dairy goat breeders are now using a test-day model to estimate the breeding value of their goats. With the test-day model, breeding values become available sooner and are more appropriate for the breeding goal of long lactations like persistency. The new service is provided by Elda and developed in collaboration with Animal Breeding & Genomics Centre of Wageningen UR. The test-day model replaces the formerly used lactation model.
Selection for persistency
The breeding value analysis will be done multiple times per year instead of once a year like in the lactation model. The estimated breeding values are summarised in two selection indices. The first one aims at dairy goat producers that strictly work with a kidding for each goat every year. The second aims at dairy goat producers focussing on long lactations. Genetic selection for persistency in addition to total yield enhances the suitability for long lactations.
The previously used lactation model only analysed the total yield in 305 days. However, many dairy goat producers aim for much longer lactations with some lactations extending to well over 1,000 days. Genetic selection for suitability for such lactations was not possible with the lactation model. The test-day model includes test-day records up to 750 days in lactation and, using MiXBLUP, allows the estimation of breeding values for both total yield and persistency of production.