Committee Technical Sessions:
Live Animal, Carcass and End Point
Temperament Assessment Provides Insight Into Future Health and Growth Performance of Beef Cattle
BOZEMAN, Mont. (June 2, 2011) — The Beef Improvement Federation (BIF) Live Animal, Carcass and End Point Committee met Thursday afternoon in Bozeman, Mont., for a technical session chaired by Robert Williams of the American-International Charolais Association.
Rhonda Vann, research coordinator and research animal scientist at the Brown Loam Branch Experiment Station in Raymond, Miss., addressed the committee. In her presentation entitled “Temperament Assessment Provides Insight into Future Health and Growth Performance of Beef Cattle,” Vann expounded on the research she is conducting to study the combined effects of transportation stress and animal temperament on real-time ultrasound body composition traits.
Stressful events can lead to the secretion of several different stress-related hormones in cattle, Vann explained. Excessive or chronic stress has been said to have a negative impact on growth, reproductive function and immune function.
Assessments of cattle temperament can be evaluated using chute-scoring, pen-scoring and exit velocity.
- Chute-scoring is evaluated on a 1-to-5 scale, where “1” indicates a calm animal with no movement. “5” indicates an animal exhibiting continuous vigorous movement, shaking of the device in which it is contained, rearing, twisting or violently struggling.
- Pen-scoring takes a similar approach, but instead measures the animal in a pen of three to five animals and an observer. Animals are again ranked on a 1-to-5 scale, with “1” indicating a calm animal and “5” indicating a very temperamental animal.
- Exit velocity is an objective temperament measurement that measures the time it takes for calves to traverse a distance of 1.83 meters out of the chute. Generally, the higher the exit velocity of the animal, the more temperamental it is considered.
Animal temperament has been shown to have negative effects on both dairy and beef cattle. Cattle with higher, more excitable temperaments exhibit lower body weights; produce less-tender meat and lower carcass weights; show inhibited milk production; show increased amounts of bruise trim due to injuries acquired during transportation or handling; and reduced average daily gain (ADG) in feedlots combined with treatment costs.
Rectal temperatures were taken during transportation. Temperamental bulls possessed greater rectal temperatures than their calmer counterparts. They also possessed larger concentrations of stress-related hormones.
Each study conducted by Vann and her colleagues suggested that temperamental cattle react differently to various management practices. Perhaps the most significant observation is that human-animal interactions are the most stressful events that these animals encounter day-to-day.
Ultrasounds were also taken on the bulls prior to and following transportation. It was discovered that as the distance traveled increased, intramuscular fat values decreased. It was concluded that stress induced by transportation has negative effects on body composition. Overall temperament score, however, did not have an effect on these traits.
The study concluded that there is a relationship between temperament and important indicators of an animal’s physiological status, including internal body temperature and pulsatility index. The data also indicated that the subjective pen score method and the objective exit velocity measurements had the highest heritability values compared to a single method.
To listen to this presentation and to view the PowerPoint and the proceedings paper that accompanied it, visit the Newsroom at www.BIFconference.com.
BIF’s 43rd Annual Research Symposium and Annual Meeting was hosted June 1-4 on campus at Montana State University, Bozeman, Mont.
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