Cattle temperament plays a large role in performance.
By: Elaine Grings, Cow/Calf Management & Production Specialist, SDSU Extension
How important is it to cull those cows with excitable temperaments? Being a ‘good mother’ can be an important trait in a cow for protecting her calf, being too aggressive can have negative consequences. Excitable cattle tend to have high levels of the stress hormone, cortisol, in their blood, which can affect health, reproduction and growth in your cattle.
Temperament can be quantified by using several tests when working cattle in chutes. A chute score is a 5-point scale (1= calm, no movement, 2 = restless movement, 3 = frequent movement with vocalization, 4 = constant movement, vocalization, shaking of the chute, 5 = violent and continuous struggling) that can be assigned when cattle are in the chute. Exit velocity or flight speed has been measured by researchers using infrared sensors. Researchers in Colorado compared flight speed measured by sensors to an exit score (1 = walk, 2 = trot, 3 = run) assigned by an observer and found the exit score to be well related to flight speed and negatively related to average daily gain. Averaging an exit and chute scores to give a temperament score gives a better indication of expected animal performance than either score alone as they are likely measuring slightly different behaviors.
Research in Oregon has shown effects of temperament on reproduction in beef cattle. Over four hundred spring-calving range cows at two locations in eastern Oregon were tested for temperament using both a chute score and measurement of exit velocity from a squeeze chute. About 25% of the cows were scored as aggressive and these cows had lower pregnancy rates (89%) than the adequate temperament cows (95%). At one location, cows were bred by AI followed by turn out with a bull. The second location used natural service mating only. The lowered pregnancy rate even when bulls were used indicates that the effect was not due solely to stress during handling at AI. Based on this and other studies, the researchers suggest culling on temperament or adapting cattle to handling to maximize reproductive performance in beef cows.
Increased handling of heifers may help them to become adjusted to the handling process and to humans. The same researchers in Oregon conducted a study to evaluate the effect of acclimating heifers to handling on reproductive performance. After weaning, they divided heifer calves into two groups. One group was processed through a handling facility three times a week for four weeks. Heifers receiving more frequent handling reached puberty at an earlier age than their herdmates, but pregnancy rates after AI were not different. The more frequently-handled heifers had lower exit scores than those handled less frequently, but chute scores did not differ between the two groups. The research therefore suggests that training heifers to handling may decrease days to puberty. They do caution that this training needs to occur when animals are fairly young because older cows did not change their temperament behavior when handled more frequently. A recent study conducted in Louisiana did not find a relationship between temperament score and pregnancy status in beef heifers, but did see a negative relationship of score to weight gain, with heifers with higher scores gaining less weight.
Temperament can affect your bottom line beyond reproduction. Cattle with excitable temperaments can have decreased growth rates as a result of altered metabolism associated with high levels of stress hormones. These hormones can affect how energy is used by the body and can affect stores of protein and energy. Not only does this affect rate of gain, but can also affect carcass characteristics by the effects on body energy stores. In addition, cattle with excitable temperaments tend to have more bruising on the carcass and increased incidence of dark cutters.