Modulation of Conception rate and Plasma biochemical profile in repeat breeding holstein friesian cows by hormonal therapy

Twenty four repeat breeding HF cows were divided at random in 4 groups each of 6 animals to study the relative efficacies of different hormonal therapies over control at breeding (GnRH 0.02 mg; LH/hCG 1500 IU; Progesterone 500 mg; all i/m) to improving their reproductive efficiency together with the weekly profile of plasma total protein, total cholesterol and triglycerides for 7 weeks post-treatment. The conception rates obtained following 3 treatments were 66.66, 83.33 and 50.00 %, respectively, against 33.33% (2/6) in control untreated cows (P<0.01). The mean protein content was significantly (P<0.05) higher in LH treated group as compared to GnRH and progesterone treated groups (9.85±0.11 vs 9.56±0.09 &. 9.41±0.10 g/dl) and even in the control group (9.74±0.09 g/dl). The weekly mean plasma total cholesterol and triglycerides levels in GnRH, LH and progesterone treated as well as control groups of repeat breeding cows varied significantly (P<0.05) in a narrow range with an overall means of 221.29±0.70 and 61.71±0.63 mg/dl, respectively. The cholesterol level was significantly (P<0.05) lower in GnRH treated group as compared to LH and progesterone treated groups and even control group. The mean cholesterol level in conceived and non-conceived groups of repeat breeding cows was 218.34±1.15 and 223.79±0.77 mg/dl (P<0.01). The levels were higher throughout the 7 weeks period in nonconceived than the conceived group, but differed significantly (P<0.05) only on day 21, 28 and 35 post-insemination and in the pooled values. The triglycerides levels in conceived cows were significantly (P<0.05) higher than in non-conceived cows (63.19±0.70 vs 60.45±0.99 mg/dl). Better conception rate with relatively higher cholesterol profile in GnRH and LH treated cows could be associated with rise in plasma progesterone, which probably sustained pregnancy in repeat breeding bovines.