Speed measurements of cattle as they exit from the squeeze chute may be a more accurate and less subjective way to assess genetic differences in temperament than scoring cattle behavior in the squeeze chute.
R.D. Randle and J.F. Baker from Texas A&M University and the University of Georgia, respectively, report that calves with high exit speeds had lower weight gains compared to cattle that exited more slowly. Exit speed was measured by two infrared sensors placed 6 ft. apart in front of the squeeze chute. The sensors started and stopped a timing device. The researchers found that heifers exited faster than steers.
For beef calves, both exit score and the traditional chute scoring system will work well. Exit speed measurement is especially recommended for old, tame cows that are accustomed to the squeeze chute. Cows acclimated to the squeeze chute tend to stand still, but speed measurements were less affected by previous experience.
In these experiments, the cattle were handled quietly so that rough handling or excessive use of electric prods was not the cause of high speed measurements. On most ranches and feedlots, more than 90% of the cattle can be moved with no electric prod. Cattle feeders report that quiet handling during re-implanting enables cattle to go back on full feed more quickly.
Improving Temperament Assessment
In these experiments, chute scores were done with a three-point rating of 1 — calm, 2 — normal and 3 — wild. A four-point system may work better and be less subjective. The ratings would be 1 — still, no movement; 2 — intermittent movement or restless; 3 — continuous shaking of the squeeze chute; and 4 — wild, berserk, violent struggling and attempting to escape. The advantage of a four-point system is that there is no middle score.
On many ranches, the use of the infrared sensors may not be practical. Australian researchers used a radar camera to measure exit speed. One advantage is that the radar unit can be placed high above the ground and is therefore less likely to be broken.
Gait scoring during exiting can also be used. As cattle exit the squeeze chute, the gait is recorded as 1 — walk, 2 — trot, 3 — canter and 4 — run. The gaits are the same as horse gaits.
In a study Jennifer Lanier conducted at Colorado State University, exit-gait scoring worked better than chute scoring. The study, which was reported in the July 2002 issue of BEEF (“A New Spin On Fertility,” page 16), showed cattle that had thin foreleg bones, exited faster than cattle with thick bones. The chute scores showed no differences.
Randle and his colleagues found that exit-speed measurements showed significant differences between Brangus and Braford cattle. Brangus cattle had faster speed measurements.
Both genetics and experience will affect temperament scores. When cattle are handled quietly, exit-speed score is less affected by previous experience than chute scores. For any temperament scoring system to work, cattle must be handled quietly. Temperament assessment will also be more accurate if the same people work the entire group of cattle. The person moving cattle in the crowd pen should not change.
Temple Grandin is an associate professor in Colorado State University's Department of Animal Sciences. Visit her Web site at www.grandin.com.