When To Castrate For Best Weights Later On27 May 2014
Beef and dairy farmers are being told that, as a rule of thumb, earlier is better when castrating bull calves.
However, there is no simple answer when dealing with castration considerations, according to Stacy Campbell, Extension Agent, Ellis County, Kansas.
Stacy's view is that there is a wealth of research out there and depending on whether it is weight gain, beef quality of whether bulls or steers are better, it is possible to find at least one paper to support your view.
The 2008 National Animal Health Monitoring System data indicates 77 per cent of bull calves in the U.S. are castrated before marketing, and 75 per cent of those are castrated before 3 months of age, writes Stacy.
With regard to age at castration, does the science support this timing or should we delay castration of bulls to gain some additional weight?
In case studies that compare implanted steers to intact bulls at weaning show no difference in weaning weight.
Low-dose implants given at 2 to 4 months of age are one of the most underused technologies in the beef industry, explains Stacy. This suckling implant will add approximately 20 pounds to calf-weaning weight.
Calves castrated (surgically, banded or emasculated) at or after weaning show increased stress, sickness and death loss. This becomes not only a financial issue - less profit for the cattle owner - but an animal-welfare issue.
Calves castrated after weaning have increased gain up until the time of castration. But when compared to calves castrated at less than 3 months of age, those castrated late in life weigh 20 pounds less at slaughter and are marketed 12 days later than those castrated early in life. Although a bull weighs more than a steer (non-implanted) at weaning, the stress of castration at this later age sets the calf back, and he never catches up.
There seems to be no difference in using a rubber band or a knife to castrate calves less than three days of age. If you've never banded a baby calf, be sure you "count to two" before securing the band. Your veterinarian might say some unkind words if he has to peel a testicle away from the scar tissue that is around that retained testicle some months later.
Do It Early
In an ideal world, a calf would be castrated after a full belly of colostrum is ingested, but I know how hard they can be to catch at 24 hours of age.
Calves castrated before three months of age show no differences in performance, health and carcass traits to calves castrated soon after birth.
A bull calf has a relatively modest increase in testosterone production up until approximately 7 months of age, so the "testosterone advantage" is minimal up to that point. The negatives of castrating late nearly always outweigh this minor benefit.
Bulls castrated weighing more than 500 pounds tend to have less marbling than bulls cut earlier. Beef tenderness ratings also decrease the heavier bulls are at time of castration. This becomes quite pronounced for bulls weighing more than 900 pounds at time of castration.
Bull calves are and should be discounted at feeder auctions. A 500-pound bull will sell at a $5 to $7/cwt. discount to his 500-pound steer mate. As bulls get heavier, the discount increases even more.
Castration of bull calves soon after birth is ideal in terms of physiology (lower stress). It also results in improved animal welfare, improved health and gain in the feedlot, and enhanced marbling and tenderness compared to castration at or after weaning.
Castration at less than 3 months of age is a reasonable alternative to castration soon after birth. Let's all strive for a 100- per cent rating in the 2018 NAHMS study.