Impact of pre and post-calving body condition score change on reproduction traits of Montbeliad cows in Algerian semi arid area.

This study aimed to determine the relationships between body condition score (BCS) and its change around calving and the reproduction traits. A total of 220 Montbeliard dairy cows reared in four farms whose level of breeding proficiency is acceptable were included in this study. Body condition (BC) in dry and postpartum period was assessed monthly on a scale of 1 to 5. Eight reproductive parameters were recorded or calculated. The results show a significant decrease (p< 0.001) of BCS from dry period (3.40 points) to the 2nd month of lactation (2.86 points). Reproductive parameters evaluated at 63, 90 days respectively for the intervals from calving to first insemination and conception shows a good command of the reproduction conduct. A complementary analyzes show a relationship between BC before calving and all reproductive parameters (p< 0.001). The best records are observed in cows with BC at dry ranged from 3 to 3.5 points. The differences are equivalent to one estrous cycle (19 days) for reproduction intervals and 20%, 19% and 9% on pregnancy rates at 60, 90 and 120 days respectively. The postpartum body condition affects only the pregnancy rate at 60 days (p < 0.05) against the level of post-partum loss of BC poses no significant effect (p> 0.05).