Specificities of reproduction in French breed suckler cows

Abstract

Reproduction in beef cows is different compared to dairy cows. An increase in reproductive performance is a key factor by which to improve productivity in beef cows. Puberty occurs when beef heifers reach 50-55% of their adult weight vs. 40-45% in dairy breeds. Beef heifers can be bred at 70% of their adult weight vs. 60% for dairy heifers. Replacement rate is low in beef production, from 18 to 30% depending on the breed. Beef cows have a longer anœstrous period after calving compared to dairy cows because the calf suckles its dam. The expression of oestrus is high in beef cows: the length of œstrus expression is between 6 and 10 hours in the 3 specialized French beef breeds (Charolaise, Limousine, Blonde d’Aquitaine) and 90 to 100% of cows express standing behavior at œstrous. Natural service is the most frequent breeding technique used in beef production: only 3 to 24% of calves are produced by artificial insemination depending on the breed. The fertility of beef cows is currently poorly understood. Reproductive efficiency is estimated by calving interval which is between 379 and 444 days depending on the breed. The prevalence of endometritis is high in both beef and dairy cows (levels of 20% have been recorded after 50 days postpartum) but its effect on reproductive performance has rarely been explored in beef cows. The present paper presents a large amount of French data concerning specialized and hardy French beef breeds.