Effects of Temperament on the Reproduction of Beef Cattle

Abstract

Temperament is often defined as the behavioral expression of animals in response to human interaction. Cattle temperament can be evaluated using an association of chute score and exit velocity, with cattle then classified as adequate or excitable temperament. To assess the impacts of temperament on various beef systems, these evaluation criteria were associated with productive and reproductive parameters of Bos taurus and B. indicus-influenced cattle. Consistently across studies, excitable cattle had greater plasma cortisol compared to animals with adequate temperament. Studies also reported that excitable beef females have poorer reproductive performance compared to calmer cohorts, including reduced annual pregnancy rates, decreased calving rate, weaning rate, and kg of calf weaned/cow exposed to breeding. Acclimating B. indicus × B. taurus or B. taurus heifers to human handling improved behavioral expression of temperament and hastened puberty attainment. However, similar benefits were not observed when mature cows were acclimated to human handling. Collectively, temperament of beef females measured via behavioral responses upon human handling impacts their reproductive and productive responses independent of breed type, and should be considered for optimal beef cattle production.

Keywords: beef cattle; behavior; cortisol; production; reproduction; stress; temperament.

Figure 1

Proposed scheme of circulating concentrations of cortisol (not in scale) in excitable vs. adequate cattle in response to perceived threats (i.e., human handling for blood collection). It is speculated herein that basal levels of cortisol are similar between two temperament types, according to assessment of chronic stress via hair cortisol analysis [31]. Sampling events are perceived as threats by beef cattle, eliciting a stress neuroendocrine response. Peaks represent the blood collection moments, in which the differences between temperament types are noticed and described in literature [4,27,28,29,35,36].