Induced Lactation Using a Half Udder Approach

Milk production during lactation normally follows the hormonal stimulation provided during a full-term pregnancy. Non-pregnant females can also be induced to lactate if given the correct hormonal stimulation. The objective of this class-based research project was to induce lactation in eight non-pregnant Holstein cows while using a half udder approach to co-administer hormones directly into the mammary gland with a goal of evaluating ultimate milk production. Non-pregnant cows were treated with estrogen (0.075mg/kg) and progesterone (0.25 mg/kg) for nine days to induce mammary growth and development. During this period the left side of the udder was infused with saline while the right side was administered estrogen (1 ng) and progesterone (2.5mg ) on 3 occasions. Two injections of dexamethasone were then administered on days 20 and 21 to initiate lactation. Cows were then milked daily. Milk production was recorded daily. As hypothesized, the treated side of the udder produced more milk without any effect on milk composition. This study indicates that a localized dose of hormones can increase the amount of milk produced during lactation.