When to castrate bulls
The special tonight is Rocky Mountain oysters, calf fries, prairie oysters, cowboy caviar or swinging beef, or whatever you call them — bull testicles have been eaten by ranchers for centuries. It’s safe to say that this has appalled and fascinated many city slickers.
The question for you is? When do you castrate your bull calves? There has been a notion intact bull calves may grow faster than steer calves, delaying castration until weaning (around 6 months old) can yield similar benefits to growth promoting implants administered when calves are one to three months of age, but without additional cost.
However, a University of Arkansas study showed that calves castrated near birth had the same lifetime average daily gain as those castrated after weaning (implanted in feed yard only). At slaughter, there were no differences in hot carcass weight, yield grade, quality grade, and marbling score.
Researchers at Kansas State University reported that, following a 28-day backgrounding period, calves that were castrated at 90 days of age (early) and received a growth promoting implant had a 17-pound weight advantage over calves that were castrated at weaning (late; 226 days of age) or castrated early without implanting.
Early castrated calves that were not implanted and late castrated calves performed similarly. These results indicate that early castration paired with growth promoting implants may yield more total pounds than either early or late castration alone when using a backgrounding program.
Researchers from Arkansas and Kansas also point out that bull calves marketed through conventional channels have historically suffered a price discount of around $4.50 to $6 per hundred weight.
Additionally, researchers from Nebraska have shown that as age of castration increases, weight loss resulting from the procedure increases. Further support for castrating calves as young as possible can be found in another study from Nebraska, which showed that steers castrated at less than 500 pounds exhibit greater marbling than steers castrated weighing more than 700 pounds.
Of course, if all calves were castrated early, we wouldn’t be enjoying these Mountain oysters.