Scientists at the U.S. Department of Agriculture’s Livestock Behavior Research Unit at West Lafayette, Indiana, have found that calves castrated shortly after birth suffered less stress and recovered faster than those castrated around weaning time.

The researchers used two different methods of castration – surgical and banding – on three separate groups of Angus, Simmental and crossbred calves: Two groups were castrated and one was not. In banding, a tight rubber band around the animal's scrotum cuts off the blood supply to the testicles. After several days, the scrotum drops off. Cattle producers prefer this method because it's less expensive and not as labor?intensive as surgically removing the testicles.

The West Lafayette researchers castrated one group of animals at 36 weeks – considered a typical age for weaning and castration. They castrated the other group at 33 weeks of age, or 3 weeks before weaning. They measured the calves' stress level by checking blood levels of haptoglobin, a protein the liver makes when an animal is injured. They found that haptoglobin levels were higher in calves castrated at 36 weeks than those castrated at 33 weeks or at birth, indicating a higher level of stress for the older animals. Surgically castrated calves also showed higher levels of haptoglobin compared with those castrated by banding.