Effect of Somatotrophin and Oxytocin on the Mammary Gland Development of Goats Treated with Estrogen and Progesterone

Neither the addition of somatotrophin nor oxytocin to estradiol and progesterone injections caused an increase in the udder alveolar surface area or milk production of virgin yearling goats as compared to estradiol and progesterone alone. The total alveolar surface area and milk production resulting from any combination of hormones used for inducing mammary gland growth was less than half of that of the goats whose adders were developed through pregnancy. All hormone-treated groups showed a deficiency of total alveolar surface area. The correlation of previous 4-wk. milk production and total alveolar surface area was 0.947. Goats injected with growth hormone started out at a higher level of milk production than the two other hormonally induced groups. No histological abnormalities were observed in the hormone-treated groups.