Fertility in New York Artificially Inseminated Holstein Herds in Dairy Herd Improvement

This was a field study to gain information on fertility of New York dairy herds and factors influencing it. Data were from 125 Dairy Herd Improvement Holstein herds with 9,750 cows. All breedings to milking cows were by artificial insemination. Herds were further selected with equal numbers of small and large herds and free-stall and conventional (stanchion) housing. Conception on first service averaged 50% and the 60 to 90 day nonreturns, 58%. Interval from calving to first service averaged 87 days and days open 116 days. Intervals between first and second service averaged 41 days and between second and third service 40 days. A total of 76 and 89% of all cows were pregnant on the first two and first three services.