Effect of recombinant bovine somatotropin (rbST) on growth of buffalo calves

Sixteen healthy calves, between 12 to 18 months of age and weighing between 70 to 180 kg were used in this study. They were assigned into various groups such as A. B; C and D and placing four calves in each group. Group A was kept as control while group B, C and D received rbST treatment @ 0.5mg/kg b.wt. on alternate day, weekly and fortnightly respectively. They were fed ad libitum consuming a high-energy protein ration and kept for two weeks adaptation period and fourteen weeks treatment period. Average body weight was recorded as 156.88, 171.64, 164.54 and 157.95 kg in group A, B, C and D respectively. The results revealed that group B that received rbST @ 0.5 mg/kg b.wt. on alternate day showed significantly increase in body weight, followed by group C and D which received rbST @ 0.5 mg/kg b.wt. on weekly and fortnightly respectively compared to control group. Body weight increased significantly in group B calves, while there is no signifi cant effect were found in the body weight of calves belong to group C and D. The results revealed that feed consumption during treatment period was not significantly different in rbST treated groups compared to control group A. Feed efficiency was significantly increased (P less than 0.01) in group B with an average of 12.98, 8.48, 10.99 and 12.75 for group A, B, C and D respectively and significant changes were noticed between group A and B, B and D during study period. rbST treatment has adverse effect on the RBCs, Hb and PCV. Average RBCs concentration was found as 4.15. 3.95, 4.06 and 4.10 x 10(6)/ul in group A, B, C and D respectively. The average Hb level in group A, B, C and D was recorded as 9.80. 9.13, 9.31 and 9.57 g/dl respectively. PCV in calves were determined and were found to be 26.98, 25.76. 26.33 and 26.62 % in group A. B; C and D respectively. Similar to RBCs and Hb decrease in PCV was also noticed between rbST treated calves compared to control calves. No s et pattern of variation was visualize during treatment period in WBCs concentration. It was revealed from present study that when given rbST @ 0.5 mg/kg b.wt. on alternate day to calves showed highest increase in glucose level compared to control calves. On the other hand Group C and D which received rbST @ 0.5 mg/kg b.wt. on weekly and fortnightly also showed increase in glucose level compared to control group (A) but this increase is non-significant. Protein level during treatment period was decreased in rbST treated calves and recorded as 7.09, 6.75, 6.71, 6.81 g/dl for group A, B, C and D respectively, from present finding that group B and C exhibited decreased protein level compared to control group A, while there is no significant difference occur between the level of protein in group D compared to group A. The total lipid level of calves during treatment period was found to be 488.41, 524.48, 506.30 and 494.95 mg/dl in group A, B, C and D respectively. Sodium level on the other hand remained unchanged during adaptation as well as treatment period between groups. The effect of rbST on potassium level in the blood of calves was relatively constant during adaptation period, while increased slightly during treatment period with an average of 4.54 in group B, 4.50 in group C. 4.46 and 4.40 mEq/L in group D and A respectively. The growth hormone level in the blood of calves was highest in group B, i.e. 9.12 ml and it was significantly different from other groups A, C and D that had growth hormone level as 3.56; 6.67 and 4.20 ng/ml respectively. The highest increase in growth hormone level was recorded in group B followed by group C in the treated animals; whereas no change was observed in growth hormone level of group D as compared to group A.