Milk production and hormonal changes in Murrah Buffaloes administered recombinant Bovine Somatotropin (rBST)

Abstract

Investigation was carried out to determine the influence of short term administration of recombinant bovine somatotropin (rBST) on plasma growth hormone (GH), Insulin like growth factor-I (IGF-I), prolactin (PRL) and milk production of buffaloes in early lactation. Experimental buffaloes received i.v. rBST infusion in jugular vein @ 5mg/hr. i.v. for 5 days, while control group was given placebo injection. Blood samples were collected for 5 consecutive days before, during and after treatment and plasma GH, IGF-I and PRL levels were measured. Administration of rBST increased plasma GH (P<0.01) and IGF-I (P<0.01) concentration simulating to increased milk yield (P<0.01). Milk IGF-I concentration was more after cessation of treatment (P<0.05) than before and during the treatment period. The milk yield increased by 29.9% during the experiment (P<0.01) in comparison to control. rBST treatment influenced milk protein (P<0.01) and lactose (P<0.01) without affecting plasma glucose and NEFA, milk NEFA, citric acid and fat content. There was no adverse effect of rBST on mammary health and plasma prolactin concentration. The positive correlation of GH and IGF-I with milk yield indicated a galactopoietic effect of both the hormones to augment milk production in buffaloes.