Modelling and optimising the Swiss pig breeding scheme. A comparison of the interest of central testing stations in Switzerland and France

In Switzerland the central testing station is currently used to test slaughtered full sibs (2 females and 2 castrates) of onfarm tested boars and sows. The equipment and sanitary status of the station are compatible with the station testing of candidates. A deterministic, dynamic model was developed to model the Swiss Large White nucleus population and predict its genetic evolution over time when artificial insemination boars were on-station tested. Several selection strategies were simulated, involving on-station testing of 1 or 2 boars per litter, with a variable number of slaughtered full sibs. Compared to the current strategy, the on-station testing of AI boars provided an extra-genetic gain of 8 to 22 % in the breeding goal, due to a higher accuracy of genetic evaluation. The optimal strategy was to test two boars and one slaughtered full sib per litter on station, but using only 50% of the station for this type of testing. We found conclusions different from those of a previous study carried out on the French selection scheme, where the on-farm or on-station testing of AI boars did not significantly change the scheme efficiency. Actually, on-station tests are a more important part of the scheme in Switzerland, in number but also from the larger economic weights of station traits in the breeding goal.