Early in gestation, the embryo forms the various organs. This is followed by linear skeletal growth until day 200. The synthesis of muscle tissue only really starts halfway through gestation, but most of the muscle is not produced until the third and final stage of gestation. Therefore, foetal growth during the final stage of gestation will require the most nutrients.

However, it is also essential to provide adequate nutrition to pregnant cows during the first part of the gestation period. Insufficient nutrition, while not directly affecting the ultimate weight of the calf, can lead to delayed growth of the future calf and may cause long-term problems (usually reproductive and health-related issues).