Cattle temperament is a focus area for research with the aim of reducing the potential for injury to producers and to preserve the longevity of facilities. One of the main objectives of cattle temperament studies is to determine if selecting sires based on temperament is effective for reaching these goals.
Researchers found that calm cattle had enhanced production traits (greater average daily gains (ADG), hot carcass weight, marbling scores, etc.) when compared with excitable cattle. However, some negative production traits have also been reported for calm cattle and include greater back fat and yield grade. Although much of the focus regarding cattle temperament is on production, no study has examined its influence on bull behavior, and indicator of well ‐ being, while enrolled in an 84 ‐ d performance test.
Researchers at the University of Tennessee examined the relationships between temperament, behavior, and growth of bulls enrolled in the 2013 ‐ 2014 junior bull test at the UT Bull Testing Station in Spring Hill, TN. The study used 60 Black Angus bulls for the entirety of the bull test program. Data collected through the testing program included the following: weight, ADG, frame score, and carcass ultrasound measurements. Temperament was assessed by assigning pen scores (1: docile – 5: very aggressive) to each bull and recording exit velocity (the rate to traverse 1.83 m). Pen scores were assigned on d ‐ 1, 27, 55, and 83 and exit velocity was assessed on d 0, 28, 56, and 84. Dataloggers were also used to record behavioral data including daily lying time, lying bout duration and frequency, and total steps taken during two, 28 ‐ d periods. Over the 84 ‐ d testing period, average exit velocity decreased, while pen score remained the same for all bulls. Bulls were split into two categories, calm and excitable, based on initial pen score and exit velocity.
Results indicated that bulls initially deemed excitable became calmer as shown by a decrease in pen score and exit velocity (Figure 1). Similarly, bulls grew accustom to the working facilities and exited the chute three times slower on d 84 than on d 0 of the test. Bulls initially categorized as excitable according to pen score had larger frames and greater ADG than calm bulls. However, the greater ADG for excitable bulls is attributed to their larger frame instead of being a result of temperament. Bull temperament was not as variable as one might see in a large herd or among feedyard cattle.
So, the minimal production differences attributed to temperament in the present study may be due to lack of temperament variation. Although there were minimal differences in the behavior data collected via dataloggers, the results did not suggest that temperament had an overall impact on well ‐ being since average lying time, number of lying bouts, and total steps taken were similar to values previously reported for cattle.
In summary, because many producers select cattle based on temperament, its variation was limited for the bulls enrolled in the 84 ‐ d performance test. So, slight differences were observed for performance and behavior. Additionally, conditioning was observed over the testing period and the initial temperament assessment, whether pen score or exit velocity, may not be a true indicator to the bull’s adapted disposition for performance tested bulls.