NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

October 29, 1998

Act Now to Improve Lagging Cow Pregnancy Rates

The effects of last summer's hot, humid weather may be showing up now as reduced cow pregnancy rates. The result will be extended calving intervals for a portion of the herd and the situation may become worse if efforts aren't made to improve heat detection soon says a North Dakota State University dairy specialist.

"Dairy producers on DHIA (Dairy Herd Improvement Association) records can quickly detect problems in herd reproduction. But those without any formal recordkeeping may be just beginning to recognize cows were not settled or did not breed as expected," says J.W. Schroeder of the NDSU Extension Service. "If your herd slipped this past summer, you should consider instituting an aggressive heat detection and artificial insemination program during the next few weeks."

Such a program would involve more frequent periods of heat detection when and at a location where cattle are most likely to exhibit heat. Estrous detection aids could be used during this period to improve the efficiency of heat detection. Generating a daily list of cows due for insemination and those due to return to heat should help focus attention on specific groups of cows that need closer attention. The attention of all employees should be directed toward improving heat detection.

This may be the time to institute an estrous synchronization program to improve the efficiency of heat detection and, ultimately, pregnancy rate during a short period of time, Schroeder says. Several programs using reproductive hormones like prostaglandin or a combination of prostaglandin and GnRH are being used by dairy producers on a routine basis to systematically manage reproduction. Potential benefits of such programs include improved efficiency of heat detection, more timely insemination, concentration of labor toward reproductive management during specific periods, and improved pregnancy rate.

"If you are interested in developing a synchronization program, consult your veterinarian and A.I. technician and work as a team to implement and carry out such a program," Schroeder says. "If pregnancy rates have been set back this summer, then consider implementing an aggressive heat detection or synchronization program immediately so no further time is lost."

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Source: J.W. Schroeder (701) 231-7663

Editor: Tom Jirik (701) 231-9629