Factors affecting reproductive performance in Ontario dairy herds.

Data were collected on reproductive, health and production events in 45 dairy herds in southwestern and eastern Ontario, Canada, from July 1990 to July 1993. Mean and median days in milk at first estrus, at first service, and at conception were 85.1 and 83.

Risk factors for twinning in dairy cows.

Records for 52,362 lactations over a 10-yr period from 260 dairy farms in North America that used a common commercial software for record keeping were evaluated for potential risk factors for twinning. Records were evaluated for the associations of reproductive disease, parity, production, drug therapy, and the occurrence of subsequent twins. The rate of twinning on these farms steadily increased over the observation period from 1.

Relationship of production to reproductive performance in Ontario dairy cows: herd level and individual animal descriptive statistics.

Data were collected on reproductive, health and production events in 45 dairy herds distributed throughout southwestern and eastern Ontario. The data were collected between July 1990 and July 1993. The herds were serviced by 11 different veterinary practices.

Evaluation of the benefits of the timing of pregnancy testing by transrectal palpation in dairy cattle.

Objective: To determine the benefits that were associated with pregnancy testing by use of transrectal palpation during the period 30 to 65 days after unsuccessful insemination of dairy cows.

Design: Nonconcurrent, cohort study.

Animals: Cows in 15 dairy herds in the United States and Canada.

Options in dairy data management.

A great deal of progress has been made in the development of dairy herd management software in the last few years. At the same time, the speed, capacity, and portability of computer hardware have increased, while costs have decreased, thus encouraging use by veterinarians,dairy herd managers, and other industry support groups. A review of the literature indicates that an increasing number of producers, veterinarians, and other dairy industry service personnel are using computers and dairy herd management software in the delivery of their services (1-3,5,9-11,26-30,38,39).