Cattle classified as temperamental appear to be less susceptible to lung damage and related respiratory diseases and have decreased yield grades, but at the same time may produce lighter weight carcasses with decreased quality grade.
Researchers used 2,800 cattle at a commercial feedlot to determine cattle temperament solely by exit velocity upon arrival to identify the impact temperament had on feedlot performance. Infrared sensors were attached to the processing chute and alleyway and used to time how fast cattle exited the processing chute. Once exit velocity was determined, within each pen the fastest 20 percent were classified as temperamental and the remained deemed non-temperamental.
Exit velocity was used as a measurement of temperament because it is the only objective and practical measurement of temperament that can be applied in a commercial setting. Scientists sought to evaluate the impact of temperament on animal health and carcass merit with an eye toward using the data as a sorting tool within feedlots.
After scientists determined exit velocity, the cattle were maintained in their original pens, not sorted based upon temperament, and finished. At the end of the finishing period, the research team followed the cattle to the packer and evaluated lung damage, liver abscesses and collected all the variables for carcass data.
One of the major findings of the trial was the difference in lung damage associated with respiratory disease. The results suggest that the non-temperamental cattle had more observable damage to the lung, indicative of the animal being impacted by respiratory challenge, when compared to cattle classified as temperamental.
Research has suggested that temperamental cattle have an altered immune response and display limited clinical symptoms of illness and this altered immune response may be a more resilient immune response compared to non-temperamental.
The studies also found that cattle classified as temperamental had lighter carcass weight at harvest and decreased quality grades. More than 53 percent of the non-temperamental cattle received a quality grade of choice, compared to 49 percent of the temperamental animals.
The findings suggest that utilization of temperament may be a viable management tool for feedlots. It might provide for a unique management strategy that might increase returns on these temperamental animals. With the difference in lung damage in the temperamental cattle at the time of harvest, and previous research indicating limited clinical signs of illness in temperamental cattle, segregation may allow for some modifications to the processing procedures and management of these cattle to take advantage of this alterations.
Ty Schmidt, Ph.D., assistant professor, animal science, University of Nebraska-Lincoln, 402-472-6772; Jeff Carroll and Jeff Daily of USDA-Agricultural Research Service; Justin Waggoner of Kansas State University.
Artwork: Cattle Feedlot
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