Consequences of the inscription of local breeds in protected designation of origin cow cheese specifications for the genetic management of the herds

Abstract

In the mountainous areas of Europe with a humid climate, dairy cattle production is a major agricultural activity, and the milk is often processed into cheese according to protected designation of origin (PDO) specifications. We analyzed the extent to which PDO specifications and/or a mountain environment influence the spatial distribution of estimated breeding values (EBVs) of cows and the herd–year effects (HYEs) for milk yield (kg/lactation) and protein and fat contents (g/kg), as well as lactation ranks and calving months. The study focused on the northern French Alps. A total of 37 023 lactations, recorded in 2006, in 1153 herds were analyzed. The cows belonged to the Montbéliarde (21 516 lactations), Abondance (10 346 lactations) and Tarentaise (5161 lactations) breeds. The two factors of variation considered were the status of the commune where the farm was located in relation to PDO (three categories: area with no PDO, area with a PDO with no milk yield limit, area with a PDO with a milk yield limit) and ‘mountain’ environment (four categories based on the European regulation: plain, piedmont, mountain and high mountain). In the Abondance breed, the average lactation rank increased with an increase in production constraints due to the PDO or to a mountain environment. In the Abondance and Tarentaise breeds, grouping of calving in winter was most marked in the ‘PDO with a milk yield limit’ and ‘high-mountain’ categories. In the Tarentaise breed, no significant effect on any trait and any variable was found in the ‘PDO’ or ‘mountain’ categories. In the other two breeds, the average EBV for milk yield decreased with an increase in the constraints due to PDO, with differences of 226 and 93 kg between extreme values in the Abondance and Montbéliarde breeds, respectively. The average HYE for milk yield was higher in the Abondance breed in the ‘PDO with no milk yield limit’ category than in the other categories (+740 and +1110 kg, respectively); HYE was not affected by the ‘PDO’ factor in the Montbéliarde breed or by the ‘mountain’ factor in either breed. Concerning the protein and fat contents, the effect of the ‘PDO’ and ‘mountain’ factors depended on the trait, the variable and the breed. The proportion of individual decisions (the farmer makes the decision) v. collective decisions (breed management) concerning herd dynamics in the face of existing constraints is discussed.