September 2008
Implants are widely used because they have successfully enhanced production efficiency, reduced the cost of production, and improved profitability of feedlot cattle for the last 40 years. Anabolic steroid implants are very cost effective for feedlot producers.
Typical implant programs in feedlot cattle have been reported to improve weight gain by 15 to 25% and feed efficiency by 8 to 12% (Elam and Preston, 2004). These products increase protein deposition and cause an upward shift in the growth curve. Anabolic implants increase mature body size, and cattle should be slaughtered at heavier weights to achieve the same marbling score as non-implanted cattle (Guiroy et al., 2002).
Implants increase carcass weight substantially, and also increase carcass leanness compared to carcasses from nonimplanted cattle. Therefore, if the appropriate implants are not administered at the proper times, that could have negative effects on carcass quality grade (marbling). This problem can be avoided when implants are used correctly.
Improper implanting techniques are a serious economic concern because the resulting defects are associated with altered performance. Some resulting defects include crushing of pellets, missing (or partially missing) implants, abscess formation, and implant placement in the cartilage rather than subcutaneously.The FDA has recently approved the first combination of a delayed-release implant for feedlot cattle. Revalor-XS (trenbolone acetate and estradiol; Intervet) contains a biodegradable polymer that provide the desired release. The application of a delayed release implant may save time, labor, and reduce animal stress, but further research is needed on this product.
Tips
Some tips about implanting cattle include:
- Choose the implant strategy that matches your cattle and management. There are several implant strategies available that can really help profitability.
- Estimate date of slaughter.
- Set performance goals for the feeding period.
- Cattle under aggressive implant strategies (high-potency implants given at the beginning of finishing phase and at reimplant) achieve maximum performance and lowest cost of gain. There is, however, increased risk of lower quality grades.
- Determine the best tradeoff between feedlot performance and carcass quality.
- Select and time the initial and terminal implants to etimated days on feed.
- Develop a quality control system for implanting technique.
- Remember: Implants must be administered in the middle third of the back side of the ear.
- Use disinfectants properly.
- Incorrect placement of the implant causing implants to be lost, crushing of pellets, or abscessed implant sites will reduce results.
- Different implant strategies should take into account age, sex, weight, breed, and marketing targets.
- Take the time for quality implanting.
- Nothing substitutes good technique.
For more information see:
Guiroy, P. J., L. O. Tedeschi, D. G. Fox, and J. P. Hutcheson. 2002. The effects of implant strategy on finished body weight of beef cattle. J. Anim. Sci. 80:1791-1800.
Dr. Judson Vasconcelos, Former Assistant Professor, Feedlot Specialist
University of Nebraska, Panhandle research and Extension Center, Scottsbluff, NE