Productivité de trois races bovines françaises, Limousine, Charolaise et Salers. Bilan de 10 ans d'observations en exploitations

Abstract

Monitoring of suckler herds of Limousin, Charolais and Salers breeds were launched as early as 1971, to collect data in order to assess the potential of animal production systems and evaluate the mid and long terms evolutions. The calf-crap, the characteristics of the cattle sold and herd's dynamic constitute some of the results necessary for the interpretation of gross margins and farm incomes. Results spanning over 10 years are presented for the three breeds, with each breed studied in its own environment and production systems. The formation of the calf-crop differs. The variable ease of birth influences both the pregnancy rate and the mortality rate of the calves, in particular the perinatal period (within 48 hours of birth). The production system also play a part: i/ the variable length of the calving period has a bearing on the pregnancy rate and the calving intervals; ii/ the culled rate determines the average age of the herd; iii/ the way the culling is conducted impacts on future performances. The calf crop starts drecreasing after 9 to 11 years, and falls rapidly from 13 years on, due to the reduction in pregnancy rate and the increase of the calves' mortality rate. The maximum carcass weight of culled cows is reached at 6-7 years old, then it diminishes regularly. Price of the carcass per kg reaches its peak at 3-4 years to fall down, more rapidly for the oldest cows, even more so in the recent years. Since the first BSE crisis, quality marketing networks have looked for young cows only. Such a trend has not hurt the Charolais area (where the culled rates are above 20%). But both the Limousin area, where the culled rates are between 14 and 18% depending as the production systems, and the Salers area, where the culled rates are under 13% because of the commercial cross-breeding, have been affected. The lowering of the overall age of the herds in the Limousin and Salers areas is a collective goal. Controlling the age of the cows appears as an important factor in cattle management. The published data could be used to elaborate herd husbandry models.