A new university-led review finds that growth implants used in calves and backgrounding cattle consistently add sale weight at very low cost, without hurting fertility, feedlot performance, or carcass quality.
The study, led by researchers at the University of Nebraska-Lincoln (UNL), reviewed decades of peer-reviewed research on growth-promoting implants used in the cow-calf and backgrounding phases of beef production. Its goal was to address long-standing producer concerns regarding profitability, heifer fertility and whether early implants affect later feedlot performance.
Suckling calves
According to the study, implants increase average daily gain (ADG) in suckling calves by approximately 6-15%. A single calfhood implant adds an average of 10.4 kilograms (kg), or roughly 23 pounds, to weaning weight compared to non-implanted calves.
Importantly, that response was consistent across genetic and environmental contexts. Even in years with limited forage or poor cow nutrition, implanted calves still gained roughly 10% faster than non-implanted calves, although the absolute pounds gained were smaller in tough years.
Despite this consistency, adoption of calfhood implants at the cow-calf level has declined sharply. The UNL study cites data from more than 5 million calves sold through U.S. video auctions between 1995 and 2009, showing preweaning implant use fell from 64.3% to 26.5%. Recent marketing data suggest the trend has continued. In 2024, 40% of 851,181 calves marketed through Superior Livestock Auction were not enrolled in programs restricting implant use, yet were still not implanted. Importantly, the UNL analysis found no difference in price per kilogram between implanted and non-implanted calves. With 227-kg steers averaging $6.48 per kilogram in 2024, the additional weight from a calfhood implant translated to approximately $66 per head in added value after implant cost.
According to the UNL-led review, producers forgo implants for several reasons. Some remain unaware of the consistent weight-gain advantage, while others market cattle through non-hormone-treated or all-natural programs that prohibit implants. Practical considerations, such as labor availability, handling facilities and limited calf access prior to sale, also influence decisions.
Fertility concerns in heifer calves remain common, yet the UNL study shows that single implants administered within recommended age windows do not reduce puberty, conception or pregnancy rates. Finally, the review dispels concerns about long-term performance, noting that implanted calves entered the feedlot heavier, maintained comparable finishing gains, and in some cases, produced heavier carcasses without negative effects on feed efficiency or carcass quality when finished to similar endpoints.
Use in backgrounding
The UNL-led study found a consistent performance advantage associated with implant use during the backgrounding phase.
Reviews summarized in the UNL analysis show implants increase ADG during backgrounding by about 14-16%, with multiple studies confirming that implanted cattle gain faster than non-implanted cattle while showing no reduction in subsequent feedlot performance.
The UNL study shows that the response to implants during the backgrounding phase is strongly influenced by nutrition and expected rate of gain. Cattle managed on a higher plane of nutrition achieved greater total weight gain, while percent improvement in daily gain remained the most consistent way to compare implanted and non-implanted cattle.
Across recent trials reviewed by UNL, typical implant programs increased ADG by about 16%. Larger responses were observed only when higher implant doses were paired with cattle capable of faster growth. Head-to-head comparisons found minimal differences among approved implant products, indicating that implant selection is more important than the specific brand, although the dose should align with anticipated performance.
The UNL-led review also addressed concerns about stress and vaccination timing. Studies have shown that implanting at or near weaning did not increase stress indicators or reduce vaccine effectiveness. In some cases, the antibody response improved slightly when implanting was delayed. Overall, the authors concluded implants can be used during routine processing without compromising cattle health or backgrounding performance.
Implant carryover to feedlots
The UNL-led study noted that relatively few experiments track cattle from the backgrounding phase through finishing, largely due to cost, facility constraints and increasing animal variability later in the production system. Even so, the authors explained that the additional ADG achieved during backgrounding should, in theory, translate into heavier feedlot entry weights and, when finishing performance is not reduced, heavier carcasses.
Several studies reviewed in the UNL analysis support this expectation. In one example, implanted steers were 8 kg heavier at the end of backgrounding and produced carcasses 7 kg heavier at harvest, even though finishing daily gain and feed efficiency were similar between implanted and non-implanted cattle. Other studies cited in the study reported carcass weight increases of 23-29 kg when aggressive implant programs were used, without adversely affecting feedlot performance.
The UNL-led study concludes that across both cow-calf and backgrounding systems, implants used according to label directions and matched to nutritional conditions consistently increase ADG and add saleable weight without reducing feedlot performance when cattle are finished to similar endpoints. The research also shows that a single calfhood implant administered within the recommended age window does not negatively affect puberty or pregnancy in replacement heifers, with reproductive concerns largely tied to off-label timing or repeated use.
From an economic standpoint, the UNL authors emphasize that implants remain a low-cost, high-return tool, and that decisions to avoid them should be based only on verified market premiums rather than perceived price discounts that are rarely supported by data. — Charles Wallace, WLJ contributing editor
