Performance and health of Holstein and Montbéliarde dairy cows in organic systems
Résumé
The aim of this study was to compare the performance of Holstein and Montbeliarde dairy cows in a mixed crop dairy system and in a more restricted one, a 100% grazing system and. The total dataset contained data from 970 lactations of cows living in an experimental farm (Mirecourt, France) from 2004 to 2015. Over 44 weeks of lactation, Holstein cows produced more milk (+ 531 kg) and fat and proteins (+ 46 kg) than Montbeliarde cows, which represents a higher milk yield per body weight (+1.04 kg / kg of body weight). However, Holstein cows had poorer reproduction performances mainly in the grazing system (- 25 % of gestation rate) and they decreased to a larger extent their body weight and condition in early lactation. Holstein cows had more reproductive disorders, but Montbeliarde cows faced more lameness. On the whole, cows had more health disorders in the grazing system. Longevity between the two breed was not different because of the choice to keep more frequently Holstein cows in a prolonged lactation. Four profiles of cows were identified in terms of lactation, reproduction, body condition and health, but this classification couldn’t be predicted by their breed, their parity or their feeding constrains.