Prepartum administration of recombinant bovine somatotropin (rBST) on adaptation to subclinical ketosis of the ewes and performance of the lambs

Abstract

The aim of this study was to determine the effect of prepartum rbST injection on the metabolic profile of pregnant ewes induced to subclinical ketosis, as well as the metabolism until seven days of life and weight gain until seven weeks of life of the lambs. Twenty seven pregnant ewes of the pantaneiro genetic group were used, divided into two groups: rbST group (n = 14) and control group (n = 13). The rbST group received two applications of 1 mg/kg of rbST, at 97 and 111 days gestation, while the control group received placebo injections. There were significant differences between groups in levels of GGT in the ketosis post induction period and BHB concentrations in the postpartum period. Concentrations of glucose, urea, phosphorus, albumin, cholesterol, AST, NEFA and insulin were not different between dams from the two groups in different periods of the study (P>0.05). There was an effect of rbST on body weight observed already at fourteen days of life (P<0.0001), there was an increase in serum phosphorus levels at birth of lambs (P=0.0014), and albumin at seven days of life (P = 0.0014) of the lambs, with no difference between groups for the other metabolites. Therefore, the use of rbST was effective in increasing the weight of the lambs until the seventh week of life. In addition, rbST treatment had positive effects on the dam metabolism with reduction of liver overload, as indicated by decreased GGT after ketosis induction and decreased BHB at the postpartum period.