Production responses of lambs immunized against somatostatin

Abstract

AbstractThe production responses of crossbred lambs [Poll Dorset (♂ × (Border Leicester ♂ × Merino ♀)] immunized against somatostatin (sornatotropin release inhibiting factor; SRIF) and whose mothers were also given anti-somatostatin vaccination was investigated in this study. There were no significant differences between immunized and control lambs in term of live-weight gain, food intake, food conversion efficiency, digestibility, eating pattern, wool growth and carcass composition. The concentration of growth hormone in plasma of immune lambs was not significantly elevated, even though the lambs had a generally increasing anti-SRIF antibody titre during the experiment. The findings suggest that although the lambs were successfully immunized against SRIF, homeorhetic mechanisms maintained growth hormone and productivity traits within normal levels.