Observations on the influence of high level feeding on the ovarian activity and fertility in dairy cows.

Cows on high and low feeding levels were submitted to palpation of the ovaries and recording of the presence and size of follicles at various days of the cycle. A mid-cycle rise in follicular activity was apparent and for which the nonovulating ovary was responsible. High level feeding stimulated ovarian activity in each of the 2 ovaries throughout the cycle and follicular activity commenced earlier in the ovulating ovary on high level feeding than on low level feeding. A larger number of inseminations per conception was required by cows on high level feeding on low level feeding. The effect of ovarian activity on fertility is discussed.