EFFECT OF BOVINE SOMATOTROPIN ADMINISTRATION DURING THE LAST TRIMESTER OF GESTATION ON MATERNAL GROWTH, AND FETAL AND PLACENTAL DEVELOPMENTIN PRIMIGRAVID EWES

Twenty-five primigravid ewes were used in a preliminary study to inves tigate the effect of bovine somatotropin (bST) between 97 and 124 days of gestation, on maternal and foetal growth and development. Five ewe s (reference group) were slaughtered at 96 days of gestation, and the remaining ewes were injected daily with saline (control group: no = 10 ) or 0.1 mg/kg body weight of bST (bST group: no. = 10). Following bST treatment, five control- and five bST group ewes were slaughtered (sl aughter group). The remaining ewes (production group) were allowed to lamb, after which the lambs were slaughtered within 2 h of birth. Bovi ne somatotropin reduced the proportion of maternal body fat, but had n o major impact on wool growth, maternal gain and gross skeletal measur ements, and foetal growth and development. Maternal bST treatment tend ed to affect the number of placentomes. It should, however, be emphasi zed that these results are based on small numbers of animals and that further research in this area is required.