PAUL BECK - OKLAHOMA STATE UNIVERSITY
Implanting preweaning is one of the most cost-effective ways to increase production for the cow-calf producer, and research shows implanted steer calves outgain bull calves.
Benefits of Implanting Preweaning Calves
Research shows that implants given during the suckling phase will increase the average daily gain (ADG) of steer calves by approximately 0.10 pound per day. The increase in gains by implanting heifers is slightly better at 0.12 pounds per day. Implanting your calves before weaning is cost-effective and will increase weaning weights of both steers and heifers with very little impact on reproduction rates of replacement heifers.
Best Practices for Implanting Preweaning Calves
Most calf implants are designed to last 120 days. Calves should be 30 to 45 days old before they are implanted, and you should refer to the manufacturer's label for approved timing. Bull calves intended for breeding should not be implanted. Bull calves not intended for breeding should be castrated at the time of implanting because implants impact scrotal development, which makes later castration more difficult.
The "Oklahoma Implant" and the Difference in Post-Weaning Performance
Some producers follow the practice of leaving bull calves intact until weaning rather than castrating them at an early age. Jokingly known as the “Oklahoma Implant” in other beef-producing areas, the idea is that natural hormones produced in the testicles increase ADG and weaning weight of the calves. However, numerous research trials have shown that implanted steer calves gain weight faster and wean heavier than bull calves. This is because bull calves have very little testosterone production until they reach puberty at a much later age than normal weaning.
Maximizing the Value of Male Calves at Weaning
The stress of castration at weaning reduces post-weaning gain potential and the calf’s ability to withstand diseases typically associated with weaning and marketing. This difference in post-weaning performance of bulls versus steers is recognized by cattle buyers, as indicated by the $5 to $10 per cwt premium for steers over intact bull calves. Producers wanting to maximize the value of male calves at weaning should consider early castration at birth or at two months to four months of age and use an implant approved for nursing calves.
In conclusion, implanting preweaning calves is a cost-effective way to increase production for cow-calf producers. Using the right product at the right time can provide returns of $25 to $30 for each dollar invested in implants, helping to pay for increases in production costs. By following best practices and maximizing the value of male calves at weaning, producers can improve their bottom line while maintaining healthy and productive herds.