Some cow-calf producers implant calves they plan to sell, and most feedlots use implants to boost growth and feed efficiency. But using them effectively requires knowledge of how implants work, how to implant correctly and potential carcass effects.
There are several types of implants containing different hormones. These include three naturally occurring hormones (estradiol, progesterone and testosterone) and two synthetic hormones (zeranol and trenbolone acetate). Zeranol mimics estradiol and trenbolone acetate mimics testosterone.
Dr. Heather Bruce, professor of carcass and meat science at the University of Alberta, says growth rate and carcass quality (amount of fat on the carcass versus lean meat yield) may be enhanced by proper use of growth implants. But this can have a negative impact on meat quality (marbling, grade and tenderness).
“This partly depends on how many growth-promoting implants are used,” she says.
General consensus is that producers can advantageously use up to three implants, depending on how old the animals are when implanted and whether they are on grass or grain. If more than three implants are used before slaughter, it’s more likely the meat will be tougher and less marbled, Bruce explains. This may vary with the breed of cattle.
“We want to do a test, to see which breeds might not be helped as much by growth promotion and which ones would be helped more,” says Bruce.
Growth-promoting implants are not allowed in certain markets — cattle certified “natural” or cattle exported to European countries. Some branded beef programs and some breeds such as Wagyu don’t use implants because their goal is high-quality, highly marbled meat that brings premium price.
On the flip side, many cow-calf producers who don’t own animals through harvest or don’t sell calves into a niche market could benefit from implants just by raising a bigger animal.
“Use of steroids should be geared toward the target market’s requirements. In the current grading system, producers are rewarded for marbling and carcass leanness,” she says.
This may mean conservative or no use of implants. But the beef production landscape keeps changing, and this may also affect steroid use.
“As breeds change, this may also change the effect we might see with steroids,” says Bruce.
Some breeds marble readily; others are known for exceptional growth rather than marbling. In earlier times, European breeds were known for exceptional growth and large size whereas British breeds were known for marbling. Today, however, British breeds have been selected for fast growth as well.
“We constantly have to reassess carcass growth and meat quality and how our production practices are affecting each breed, as these breeds change over time,” she says.
A person might use only one or two implants in early-finishing cattle, depending on the target market, and possibly three or more implants in cattle that will be growing longer.
The right implant at the right time
Bruce says that they’ve found that if cattle get more than two implants — for example, an estrogen-progesterone early in the animal’s life, after weaning, then trenbolone acetate-based steroids just before finishing — toughness increases unless the product is aged post-mortem.
“If the product is aged for 14 days after slaughter, the beef that received a series of implants and a terminal implant will tenderize, but in some cases won’t reach the level of tenderness seen in animals that did not receive steroids,” she says.
It also depends on the type of steroid. “The more aggressive steroids are more likely to produce increase in toughness. Cattle producers need to understand how implants work, and best ways to use them. Typically, we use estrogen-progesterone early and trenbolone acetate just before finishing,” says Bruce.
Dr. Brian Warr, an associate veterinarian with Veterinary Agri-Health Services at Airdrie, Alta., says producers should pick an implant appropriate for production level of the animal — suckling calf, backgrounding or feedlot.
“Working with your veterinarian and nutritionist to select an appropriate implant will help you obtain optimal benefit while avoiding potential complications. Some implants are labelled for pasture cattle and others for feedlot cattle,” he explains.
“When we see wrecks, we often find the wrong dose of hormone was used or there was a timing issue and a second implant was given too soon. When designing a protocol, start with the end in mind. Project a marketing date and work backwards to make an implant protocol to optimize the right product for the right stage of production. Schedule the implants on a calendar,” says Warr.
To minimize adverse effects of steroids on eating quality, read the label and allow adequate withdrawal time before the animal is slaughtered. The implant should be given far enough ahead that all hormones will be gone from the animal’s system.
“It’s safe to eat cattle that have been implanted and not completed that ‘pay out’ period, but the meat will be tougher. With steroids, muscle focuses on making more muscle protein. Depending on the steroid, it can stop marbling. When the muscle is focused on growth, it also doesn’t have the enzymes that do natural turnover/degradation of muscle tissue, and won’t be as tender,” Bruce says.
Some producers increase dosage, thinking that if some is good, more is better. But there is no economic benefit.
“Giving an animal more than the labelled dose just costs more and you don’t get more growth, and extra dosing sometimes compromises health of the animal — and will certainly compromise meat quality,” Bruce says.
“If used properly, however, implants can be an effective production tool to optimize carcass quality without significantly impacting meat quality. They can increase the value of the animal and help keep beef production systems sustainable,” she says.
There are some new products today, mainly longer-duration implants. Different companies have used different technologies to achieve longer duration including implants with delayed release for the entire dose, implants that have two different phases of hormone release and implants with a coating to result in longer duration release of the entire product.
“Longer duration adds flexibility to the production system. There are now some implants that may last 200 days, which may be an advantage in the feedlot because you don’t have to process cattle through the chute as often,” says Warr.
“There are also longer-duration grass cattle implants that may provide a benefit because of the way producers often implant purchased cattle before they go to grass,” he says.
Feedlot people get good at administering implants because they implant many cattle, many times each year.
“Cow-calf producers, backgrounders or grass cattle owners might only implant once a year, such as before spring turnout, and it might pay to have an experienced person administer implants,” says Warr.
“Make sure you have the right tools and that they function properly. Have extra implant needles in case you dull one or bend it. Take time to become familiar with your tool, to fully understand how it works,” he says.
Sanitation is important, too.
“This can be a challenge in a branding trap. Some people use a sponge dipped in disinfectant like dilute Hibitane (containing chlorhexidine). The needle should be cleaned between each animal. Change the water before it gets dirty,” Warr says. “Don’t inject with a dirty needle or you may introduce infection. Change needles at least each time you put new implants in the gun. If the ear is dirty or covered with manure, use the other ear.
Keep implants clean as well. “We often see guys putting the implant cartridges in their pockets. It might be better to use a small Tupperware container,” he suggests.
Use of implants is often one of the most valuable things a producer can do, so slow down and do it right. When working cattle, people are generally in a hurry. But Warr says it’s important to put quality first and quantity second. Proper restraint is crucial. In the feedlot, a chute with a neck extender is helpful.
If you are implanting for the first time, read the instructions carefully or have someone show you proper technique.
“The packaging shows the location; ideally, we put the implant into the back of the ear, middle third, top to bottom. Looking at the ear from the tip to the cartilage ring where it connects to the head, you want it in the middle third and not too close to that cartilage ring, especially in feedlot cattle. We don’t want the implant to enter the carcass; we want it only in the ear. We also don’t want it too close to the edge of the ear because there’s less blood supply and potentially less absorption,” says Warr.
He adds the implant should be at least a thumb’s width from other things like ear tags or previous implant sites. It should sit just under the skin, and no deeper, for proper absorption.
After implanting, feel the pellet in the ear.
“If you can’t feel the pellets, you may have put the needle through the ear and the implant may be on the ground. It may be deep in the cartilage or maybe you only got half the implant where it should be,” says Warr.
“With feedlot cattle we can do implant audits. About three weeks later we pull 10 to 20 per cent of the animals in a pen and run them through the chute to palpate the implant. If there were any sanitation issues we’d see abscesses by then. We check for abscesses, missing implants or other abnormalities like (an implant) too deep in the cartilage, or if the implant has separated or bunched. We try to avoid crushing the implant because that affects the way it is absorbed. It might create a big spike in hormone release,” he says.