Brood Cow Productivity and Body Condition
Dr. Joe Harris

Two studies relating to cow body condition and productivity have particular application to our brood cow supplementation recommendations. Both were published in Veterinary Medical Journals. (Corah, 1993, Large Animal Vet. 48 (8): 8 and Wikse, et.al. 1995, JAVMA 207:1292) I have summarized the results in graphical form on the next page.

The first graph depicts the effect cow condition at weaning can have on productivity. Cows were palpated at weaning and a body condition score was given. The weight of the calves was also determined. In most cases, the data implies that cows that were thin at weaning time were not able to have effectively conceived during the breeding season. If they did rebreed, they often failed to maintain the pregnancy. Additionally, cows in better condition weaned heavier calves. This data serves to support supplementation to ensure cows are in proper condition to effectively rebreed.

The second chart depicts the adverse effects that failing to maintain cow body condition during late gestation can have on the survivability of calves until weaning time. Calves from cows that lost approximately 140 pounds during late gestation were only 70% as likely to reach weaning age.

Together, this information stresses the importance of maintaining body condition on cows throughout the year, as well as demonstrating the economic incentive to do so. Cows that are maintained in a body condition of 3 to 4 (on 5 scale) have a much greater chance of re-breeding and weaning a healthy calf each year. So much so that failure to maintain body condition can reduce cow productivity by 30% or more.