First introduced in the early 1950s, growth-promoting implants have evolved considerably and proven their economic value, but in many cases remain underutilized. That was a message from Kansas State University feedyard specialist Chris Reinhardt, PhD, in a presentation during the recent Academy of Veterinary Consultants conference.

Reinhardt outlined decades of research and practical experience in using implants at all production stages. Implants, he says, are the only treatment at processing that pays in every animal. Antibiotics, vaccines and dewormers provide value across the population, but some percentage of cattle would do fine without them. Implants provide about the same improvement in gains and feed efficiency for every animal, provided the implant is administered properly.

In the feedyard, Reinhardt says one key is to feed implanted cattle to a target endpoint in terms of backfat thickness or yield grade. Non-implanted cattle will reach a given endpoint sooner and at lighter weights compared with similar implanted cattle. More aggressive implant programs mean more time and more weight to reach that same fat endpoint.

That weight is what pays for producers though. The added weight gains provided by implants in calves and stocker cattle more than account for the price slide, or reduction in per-pound sale price for the heavier cattle. And, Reinhardt says, the added weight from a pasture implant stays with the animal through later production stages, meaning a calf that weighs 20 pounds more at weaning due to an implant will retain that 20-pound advantage through later production stages. There is no justification, he says, for implanted calves or yearlings to be discounted based on a perceived reduction in gain potential.

In the feedyard, a single implant containing 120mg of trenbolone acetate and 24mg of estradiol provides about a 65-pound gain advantage over no implant, while an implant strategy using two doses of a more aggressive trenbolone acetate/estradiol implant can increase gains by about 90 pounds.

Implants are known to reduce quality grade somewhat, but that reduction is minimal when comparing implanted versus non-implanted cattle fed to the same fat endpoint. Those extra pounds pay significantly more than the small improvement in quality grade gained from not implanting. Based on averages for gains and loss of grade, Reinhardt says the Choice-Select spread would need to be about $46 before the grade advantage for not implanting would pay. Currently that spread is about $12.

The effect of implants on marbling score is about the same across cattle types, but the economic impact can be greater in marginal cattle, with more dropping a grade such as from Choice to Select, compared with higher-grading sets of cattle. And of course, some branded natural-beef programs offer price premiums that can help offset the performance sacrificed by not implanting cattle.

Reinhardt says implant choices can affect the incidence of bullers in feedyard pens, particularly during the summer and in large pens. More aggressive implant programs result in more bullers, so feedyards should base their implant choices on their ability to manage bullers, especially if they house cattle in large-capacity pens.

Some feedyards delay implanting cattle for some time after arrival to reduce stress and morbidity, but Reinhardt says research has shown no significant health advantage in delaying administration of implants.

As for the use of beta agonists, which increase gains during the final weeks of finishing, Reinhardt says there is no interaction with implants in terms of performance. Implants and beta agonists work in completely different ways, so the weight-gain advantage from one product will be the same either with or without use of the other product.