Effects of Temperament,
Animal Handling on Fertility
SIOUX FALLS, S.D. (Dec. 4, 2012) — Temperamental tendencies are more apt to surface among females. It's true for bovine animals at least, according to Oregon State University beef cattle specialist Reinaldo Cooke. In a presentation during the Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium Dec. 3-4 in Sioux Falls, S.D., Cooke said females and young cattle tend to be temperamental. Animals accustomed to wide-open spaces become more temperamental when confined, and Bos indicus breeds generally are more temperamental than Bos taurus breeds of cattle.
"It means they are more nervous or excitable and they may be more aggressive," said Cooke. "The expression of temperament is a stress response, indicating the animal is outside its comfort zone. It's usually tied to fear, which causes a hormonal response. Blood concentrations of cortisol and other hormones increase, preparing the animal for fight or flight."
Some level of temperament can be desirable if, for example, it makes a range cow better able to protect her calf against predators. However, many beef producers often select for very calm, docile cattle. It generally promotes greater safety for the animals and their human handlers. Cooke said cattle temperament has implications for economic return in a beef cattle operation. Stress can impede normal metabolic processes, thus reducing production efficiency of growing cattle. Even carcass merit can be negatively affected.
"Stress can impact reproduction, as well as feeding performance and carcass traits," said Cooke. "Physiological effects include changes in hormones involved in the estrous cycle and maintenance of pregnancy. Excitable temperament can be associated with delayed onset of puberty and lower pregnancy rates.”
Cooke said it can pay to take steps to improve temperament within a beef herd, and described evaluation methods.
"Temperament can be assessed by evaluating the behavior of animals held in a chute, and scoring their behavior on a one-to-five scale," explained Cooke. "Exit velocity scoring is another way, where the score is based on the speed at which an animal leaves the chute. Both methods are usually fairly well correlated. They can be used individually, or by combining the scores and using the average as a temperament score."
Cooke advised application of low-stress animal handling techniques and noted how temperament of young animals can be improved by acclimating them to processing facilities and handling by humans. Cooke recommended producers take time to acclimate replacement heifers, in particular, while they are very young. He admitted that acclimation is often less effective with mature animals. For the worst bad actors, the best option may be culling.
Cooke spoke during Tuesday's ARSBC session focused on management of stress. Visit the Newsroom at www.appliedreprostrategies.com to listen to his presentation and view the accompanying PowerPoint and proceedings paper.
Comprehensive coverage of the symposium is available online at www.appliedreprostrategies.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproductive Task Force and LiveAuctions.tv.