Reproductive management practices among Tulare, California, dairy herds. I. Census and descriptive aspects

A census of reproductive management practices for 218 out of 234 dairies in Tulare County, California, was obtained by cross-sectional survey methods. An among-herd approach to epidemiologic studies was illustrated. Results indicated that the average herd size was 562 cows, 5.9% of the Tulare County dairy herd population was purebred, 54% had "lockup" type stanchions, 40% of dairies were "flat" milking barns and 47% were "herringbone" barns. The reproductive problem most often cited by Tulare County operators was repeat breeders (50% of operators cited this problem) followed by no major problems, abortions, cows not showing estrus, metritis, long calving intervals and cystic ovaries. On 66% of dairies, veterinary pregnancy diagnosis was routinely carried out and 49% of the dairies used a veterinarian to perform post-partum examinations. Approximately 41% of the dairies used tailchalk and a surprising 23% of dairies used prostaglandins for cowsnot showing estrus. The owner-manager was the most frequent category of estrus detector cited, followed by everyone doing estrus detection, the herdsman detecting estrus and only 2% of dairies hired someone specifically for this purpose. An examination of bivariate relationships between dairy management practices and owner-perceived reproductive problems is presented.