Effect of Body Condition Score and Parity on Resumption of Post-Partum Ovarian Activity in Montbeliard Dairy Cows under Semi-Arid Area of Algeria

A study was undertaken to evaluate and investigate the relationships among Body Score Condition (BCS), parity and serum hormonal profiles (progesterone (P4) and oestradiol-17B (E2)), and resumption of ovarian cyclicity postpartum in montbeliard cows (primiparous (n = 19), and multiparous (n = 59) in semi-arid region of Algerian. The BSC was measured at calving on a 1 to 5 scale according to the Edmonson (1989) method. Blood samples were collected by jugular venous at d30, d40, d50 and d60 post-partum (10 days interval). Progesterone and estradiol -17B concentration were determined by chimiluminescent method. Changes in progesterone concentration were used to assess the resumption of ovarian cyclicity. Cows with serum P4 concentrations ?1 ng/mL on at least two consecutive blood samplings were considered to have luteal activity. The results showed a significant increase in serum levels for progesterone and estradiol -17B during postpartum period. The correlation analysis shows that P4 concentration in cows was positively correlated with their BCS at d30, d40, d50 and d60 postpartum: (r = 0.630; r = 0.603; r = 0.622 and r = 0.467 respectively; P < 0.01) additionally, the BCS at calving was positively correlated with estradiol -17B concentration at d30 (r = 0.628); d40 (r = 0.612); d50 (r = 0.444) and d60 (r = 0.294) (P < 0.01). Furthermore, BCS at calving was strongly and negatively correlated with CCI (r = - 0.704; P < 0.01. The results of the current study provide evidence of a negative correlation between calving conception interval and secretion of P4 and E2.