Date of this Version
Trimberger, George W. (1948) Breeding efficiency in dairy cattle from artificial insemination at various intervals before and after ovulation (Research Bulletin: Bulletin of the Agricultural Experiment Station of Nebraska No. 153)
The length of estrus and the time of ovulation were determined for 46 heifers and 86 cows of the Ayrshire, Guernsey, Jersey, and Holstein breeds by testing for end of estrus and ovulation at 2-hour intervals. Services were given by artificial insemination at various intervals before and after ovulation to determine the influence of this factor on the rate of conception. No significant breed or seasonal differences were found for length of estrus and ovulation time after end of estrus among the four dairy breeds represented in the experiment.