EFFECTS OF SOMATOTROPIN ON DAIRY-CATTLE R EPRODUCTION

Currently somatotropin in being developed for use in several animal sp ecies, primarily as a productivity enhancer. The objective of this pap er was fo review direct and indirect effects of somatotropin supplemen tation on reproduction particularly in the dairy cow. There is substan tial evidence that somatotropin plays an important role in the normal ovarian function. This effect is probably mediated via IGF-1. Existing literature indicates that higher milk yields are antagonistic to repr oductive performance and require enhanced nutrition and reproductive m anagement. Similarly, studies indicate that reproductive performance m ay be impaired in dairy cattle supplemented with somatropin. Effects o f somatotropin treatment on reproductive performance may depend on me dose and the stage of lactation. Low doses of somatotropin in early la ctation may improve reproductive function.