Castrating Calves in the Spring

Did you know that the seven most dangerous words in the English language are “Because we’ve always done it that way”? This is a phrase that cattle producers commonly reply with when asked why they run their operation a certain way or on a certain timetable. For some producers, it is simply tradition that they round their calves up in the fall after harvest is finished to wean, process, and castrate them before they are sold. But is castrating large calves in the fall really best for the calves and the producer, or is it time to switch bull calves to spring castration before pasture turnout? Let’s compare calf management practices and evaluate the evidence from veterinarians and researchers.

Of all the calves marketed in the United States, 75% are already castrated before three months of age. Typically, this is performed by banding or cutting shortly after birth or when they are run through the chute before spring pasture turnout (which is also an excellent time to give their clostridial and respiratory vaccines). No major differences have been found in the performance or health of calves castrated at birth or when they are a few months old. The key is to do it as young as possible, considering what works for your operation. If you band, it is essential to get both testicles below the elastrator band and give a clostridial vaccine with tetanus when you do it. The complication rate for these castrations is nearly zero when calves are young and turned out on clean grass afterward.

Many producers believe that castrating bull calves in the spring removes their natural testosterone (a hormone that helps promote growth) too early. But studies have shown minimal “testosterone advantage” in a growing bull calf until they are about seven months old and become sexually mature. An easy way to avoid growth concerns is to implant your calves with a low-potency growth implant at pasture turnout in the spring. Low-dose implants given to calves at around two to four months old are underutilized in the beef industry. In several studies, implants have been shown to increase weight gains in young calves anywhere from 8-18% (15-40 lb.) over a summer on grass, when compared to a non-implanted calf. When fall comes around, weaning weights of implanted steers will equal those of intact bulls.

Castrating calves in the fall, either by cutting or banding with a larger callicrate band, becomes a more serious procedure due to the increased size of the calf and its testicles. Sometimes larger calves may bleed significantly from their cut spermatic cord vessels. Both calves that are cut or banded in the fall are more at risk for castration infections, especially if they are turned out into a muddy or very dusty lot following the procedure. Even with the best vaccination protocols in place, these larger calves are likely to get stressed from increased pain after castration, which can lead to an increase in pneumonia cases. Increased stress and inflammation also lead to a decrease in eating and average daily gain for several weeks after castration; the stress of castration can set a big calf back so far that he may never catch up to his pen mates castrated in the spring. One study showed that calves castrated in the fall are marketed on average 12 days later than those castrated in spring (the extra time they need to heal and increase their feed consumption again). They eventually weigh an average of 20 pounds less at slaughter than spring-castrated steers. In addition, bulls castrated at greater than 500 pounds tend to have lower marbling and tenderness scores of their meat at slaughter.

The increased risk of stress, sickness, and even death loss from castrating calves in the fall, combined with the increased costs from resulting antibiotic usage and the potential for less profit, make it an easy choice to switch your calves to a spring castration plan. Observe how many noticeable improvements you see in your operation. Castration of bull calves when young has been proven to be less stressful and painful to the calves while easily leading to the same finished product at the same amount of pounds.