Study shows that nervous cattle have reduced conception rates compared to those that are calm
Most producers will agree that they prefer cattle that are predictable, even tempered and relatively calm. While no cow has a sunny disposition all the time, it is beneficial to an operation to have animals that are as mild mannered as possible, both for safety and profitability.
A study by the University of Florida revealed that cows who are nervous and flighty are less likely to conceive.
Their animal scientists “recorded disposition scores over two years on 160 Braford and 235 Brahman/British crossbred cows. They wanted to evaluate the effects of cow temperament and energy status on the probability to become pregnant during a 90-day natural breeding season. Cows were scored as 1 being calm, no movement to 5 being violent and continuous struggling while in the working chute. Also, a pen score assessment was assigned as 1 being unalarmed and unexcited to 5 being very excited and aggressive toward technician. An exit velocity speed score was measured as the cows exited the working chute as 1 the slowest and 5 the fastest.
An overall temperament index score was calculated by averaging the chute score, pen score and exit velocity score. Blood samples were analyzed for cortisol concentrations. Cortisol is a hormone released when mammals are stressed or excited. Increased cow temperament score and elevated plasma cortisol concentrations both were associated with decreased probability of pregnancy. These results suggest that excitable temperament and the consequent elevated cortisol concentrations are detrimental to reproductive function of cows.”
Reinaldo Cooke, associate professor of beef cattle production at Texas A&M, noted that sour dispositions caused lower conception rates in both AI (artificial insemination) and natural breeding programs. Usually, those cows are able to raise calves as good as those with a calmer disposition, he said. But, in the end, there are fewer calves to sell off of them, so the overall return is lower.
He also noted that since disposition is inheritable, keeping a cow with poor temperament means there’s about a 50% chance her heifer or bull calf will also have temperament problems. Excitable temperament has detrimental effects on reproduction in beef females independent of breed,” he explained.
Dr. Heidi Ward and Dr. Jeremy Powell with the University of Arkansas Cooperative Extension Service have said overly excitable cattle are more difficult to handle and studies have indicated that calves with disagreeable dispositions do not gain as well as calmer calves.
Cattle with poor or nervous dispositions have also been found to produce darker than normal beef due to stress-induced depletion of glycogen stores prior to slaughter.
Trying to keep cows with poor temperaments, especially those that won’t conceive, creates a drain on a producer’s resources, especially after last summer’s drought in the Ozarks when feed resources are still on the scarce side.
“Cows that have poor dispositions and are hard to handle, this is the time to get rid of them,” David Hoffman, MU Extension livestock field specialist, advised.