United States beef producers are well aware of the need to increase output of high quality, safe, and affordable beef products to support the needs of increasing global beef demand. However, producers are required to meet consumer demands in an era that boasts record corn prices and nearly-impossible production costs.
Many tools and technologies are available to help increase efficient production of safe, wholesome, and palatable beef products. One technology that was approved for use in feedlot cattle by the Food and Drug Administration over 50 years ago is anabolic implants.
There are many different types of implants available to primarily increase muscle mass deposition, body weight gain, and efficiency of feedlot cattle.
Implants are comprised of pellets that contain different concentrations of estrogenic, androgenic, or a combination of estrogenic and androgenic properties. In a 1996 review of 37 feedlot research trials, implanting cattle resulted in an 18 percent improvement in average daily gain (ADG) and 6 percent greater average daily feed intake to improve feed efficiency by 8 percent compared to non-implanted cattle. Efficacy of any implant program not only depends on proper implant technique but also concentration and payout (hormone release) pattern of the anabolic hormones.
Implants must be administered appropriately so the pellets are not crushed or abscesses or infections do not occur around the administration site to ensure proper implant payout and animal response.
Traditionally, cattle are implanted twice over the feeding period. For long-term implant programs, it is generally recommended to administer an initial implant that contains low- or moderate-estrogenic activity followed by subsequent administration of an implant containing estrogenic or androgenic activity after 70 to 100 days when the payout of the previous implant is complete.
Re-implanting results in increased labor expenses due to handling cattle a second time and disruption of cattle performance as they are removed from their home pen, re-implanted, and then returned to their respective home pen.
Disruption of cattle performance is largely dependent on the degree of stress cattle experience during re-implant. This stress usually results in decreased feed intake and leads to overall gain and efficiency losses, particularly in large-pen feedlots.
In response to these concerns, a long-acting combination implant was developed by Intervet/Schering-Plough Animal Health to eliminate re-implanting feedlot cattle mid-way through the finishing period.
Revalor-XS is a growth technology product recently designed for feedlot steers fed for up to 200 days in confinement. The long-acting combination implant contains 10 pellets that comprise a total dose of 200 mg TBA and 40 mg of estradiol, which is the same hormone concentration provided in the Revalor-IS/Revalor-S combination implant program.
A patented polymer coating aids in the delayed-release technology of Revalor-XS. The first four pellets of the implant are not coated with the polymer, so they start releasing hormone immediately and continue payout for approximately 70 days.
After 70 to 80 days, the biodegradable polymer coating of the remaining six pellets has broken down to allow these pellets to start releasing hormone to initiate a second boost in feedlot performance analogous to administration of a terminal implant without associated stress to the cattle.
Three similar research experiments conducted at feedlots in Colorado, Idaho, and Texas, evaluated differences in feedlot performance and carcass characteristics of 720 crossbred steers initially weighing 570 pounds and fed for 198 days that either received a negative control implant (cattle were worked similarly to implanted cattle but only had needle insertion into the backside of the ear), or a single Revalor-XS implant at the beginning of the feeding period.
As expected, implanting steers with Revalor-XS compared to no implant significantly improved dry matter intake (DMI), ADG, feed conversion, final live weight, and hot carcass weight. There were no negative effects on average marbling score, percentage of carcasses grading low Choice, or percentage of carcasses grading average Choice or higher when implanting with Revalor-XS.
However, data of the summary suggested the percentage of carcasses grading Choice and Prime was reduced when cattle were implanted with Revalor-XS versus not implanted at all.
Also, implanting with Revalor-XS resulted in fewer yield grade 1 and greater percentages of yield grade 4 and 5 carcasses compared to non-implanted steers when fed to common days on feed. Likely, marketing implanted cattle earlier than non-implanted cattle in these experiments would have minimized the percent of yield grade 4 and 5 carcasses.
Research evaluating the performance and carcass characteristics of beef steers implanted with Revalor-XS compared with other re-implant programs that deliver the same total concentration of estrogen and TBA has suggested generally no differences in ADG, carcass gain or feed efficiency, but some improvements in carcass quality when implanting with a single Revalor-XS implant.
Research from the University of Nebraska suggested steers implanted with Revalor-XS at the beginning of the feeding period had similar carcass-adjusted DMI and ADG but poorer feed conversion than steers implanted initially with Component TE-IS followed by re-implant with Component TE-S 85 days later.
Ribeye area was smaller, but marbling score was higher for steers implanted once with Revalor-XS compared to steers in the re-implant program.
A second study evaluating the same implant treatments suggested similar feedlot performance and efficiency among steers in both implant strategies. However, implanting cattle initially with Revalor-XS in the second study tended to result in more carcasses grading Prime but fewer yield grade 1 carcasses than cattle in the re-implant program.
A third study conducted by University of Nebraska researchers compared feedlot performance and carcass characteristics in steers receiving either a single initial Revalor-XS implant or a combination of Revalor-IS followed by re-implant with Revalor-S 80 days into the feeding period.
There were no reported differences in carcass-adjusted feedlot performance variables, and major carcass characteristics were not affected due to implant strategy. However, more carcasses from steers implanted initially with Revalor-XS graded low Choice, which reduced the number of carcasses grading Select compared to the re-implant program.
Thus, implanting with Revalo-XS resulted in a greater percentage of carcasses grading Choice or higher, whereas the Revalor-IS/ Revalor-S re-implant program resulted in a greater percentage of carcasses grading Select or lower.
Results from these studies suggest relatively similar feedlot performance and carcass characteristics of steers when using a single long-acting combination implant (Revalor-XS) containing the same hormone combination compared to a traditional combination implant program that requires a re-implant approximately 80 days into the feeding period.
Most experiments also reported improved carcass quality in steers implanted initially with Revalor-XS. In addition to reducing labor costs, administering Revalor-XS to eliminate stress associated with re-implanting steers may provide an opportunity to improve quality and overall profitability of feedlot beef production, particularly if finished steers are marketed in a quality grade-based system.
Regardless of implant program, use of this technology in feedlot cattle will continue to increase efficient production of safe, wholesome, and palatable beef products for consumers.
For more information regarding beef feedlot production or any other beef-related topic, please visit the U of M Beef Team website at: http://www.