THE temperament of cattle may have a significant effect on how they perform in the feedlot, according to research by the University of Nebraska-Lincoln, Kansas State University and the U.S. Department of Agriculture.
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, according to the study by Ty Schmidt, Joe Buntyn, Chris Calkins and Kathy Domenech of the University of Nebraska-Lincoln, Jeff Carroll and Jeff Daily of USDA's Agricultural Research Service and Justin Waggoner of Kansas State University.
The research team used 2,800 cattle at a commercial feedlot to determine cattle temperament solely by exit velocity upon arrival to identify the effect 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% were classified as temperamental, and the remainder were deemed non-temperamental, Schmidt said.
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, the announcement said. The 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 — i.e., not sorted based on temperament — and finished. At the end of the finishing period, the research team followed the cattle to the packer and evaluated lung damage and liver abscesses and collected all commonly used carcass data.
One of the major findings of the trial was the difference in lung damage associated with respiratory disease, the researchers said. The results suggest that the non-temperamental cattle had more observable damage to the lungs — indicative of the animal being affected by respiratory challenge — compared to cattle classified as temperamental.
"The temperamental cattle may have more resilient immune systems," Carroll said. "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 (cattle) based upon these findings."
Schmidt and his colleagues also found that cattle classified as temperamental had lighter carcass weights at slaughter and decreased quality grades. More than 53% of the non-temperamental cattle received a quality grade of Choice, compared to 49% of the temperamental animals.
Schmidt said the findings from this trial "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 slaughter 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 these alterations, Schmidt said.
Alterations may also be introduced in terms of nutritional management or even modification of days to feed to overcome the decreased bodyweight of the temperamental cattle, the announcement said. However, before this type of segregation can be used in commercial feedlots, there is still a need to further evaluate this methodology, Schmidt added.
The next step for the research team is to determine an animal's temperament on arrival and then sort the cattle based on temperament.