Your Reading List

A solid case for the value of growth implants

Animal Health: A very safe technology for improving cattle efficiency and weight gains

beef on a winter pasture

Growth implants in the cattle industry have been used since the 1960s — way more than 40 years on hundreds of millions of cattle in North America as well as in other beef-producing countries such as Australia, New Zealand and South Africa, to name a few.

We all know the benefits that come with a very small amount of hormone delivered in the proper proportions in the ear can produce both increased gain and feed efficiency. Gains will increase (10-25 per cent) and feed efficiency will rise up to 15 per cent.

The increased feed efficiency is important. As we all know, your biggest cost in producing beef is feed. The amount of improved gain depends on the cattle type including such factors as breed, gender as well as phenotype.

The amount and quality of feed as well as the type of implant (concentration of the androgenic and estrogenic hormones) as well as the length of time the implant lasts all have a bearing on the final improvement in gain.

You can start with implants as soon as castration occurs and it is wise to implant your non-replacement heifers as well. A few implants are even approved for heifers retained for breeding but there are stipulations. Younger calves have a better feed conversion rate, so the younger you start, the quicker the gains. Work with your herd veterinarian on an implant program that best maximizes the gains possible on your ranch, realizing your management style and type of feeding program. The extra effort is well worth it.

With chutes now having neck bars and shoulder restraint devices, it is much easier to implant. Guns are designed so crushing of implants as well as bunching are pretty much a thing of the past. Make sure to wipe the implant needle through a disinfectant after each use. We want to implant properly to get the maximum benefit but we always say the worst-case scenario comes from not implanting at all.

Safety well researched

There have been a multitude of trials (hundreds) comparing implants against one another or comparing implanted versus non-implanted calves. Hundreds of these trials were done decades ago. Now the only trials one sees is when a new implant hits the market. Weight gains vary from 20 pounds to more than 50 pounds with the longer-lasting finishing implants. Most of the implants use a combination of estrogens and androgens (either natural or synthetic) to achieve better weight gains. The synthetic androgen TBA (trenbolone acetate) has more impact on growth and less on behaviour. Hundreds of millions of cattle have been implanted over the years and most multiple times with no real side effects.

Implants will return a conservative 15-25 to one return to you the producer. If you don’t implant you are leaving many dollars on the table. The optimum time to implant is right after bull calves are castrated.

Remember young calves have a greater feed efficiency and conversion rate (four pounds of feed for one pound of gain) so the younger ages are the ideal time to start most implant programs. The few exceptions to using implants would be when keeping heifers for breeding or intact bulls for breeding or keeping bulls to be castrated at an older age.

If you can market into a branded program where calves with no growth promotants are to be enrolled; that is fine but those calves should be worth in the neighbourhood of at least 20 per cent more. The extra value is needed to compensate for the extra gains and feed efficiencies you are foregoing from not being able to use the growth-promoting technologies (implants, deworming, ionophores and beta agonists). Without the implants it simply takes more time and more feed to produce the same weight of calf. Sustainability of the cattle industry becomes compromised.

We all need to know how safe growth implants are. They are all given in the ear so none of the residual product enters the food chain. Hence all implants have a zero meat withdrawal time. It would be wasted money to implant too close to slaughter. Most astute producers time it so the effect of the impact is almost running out just prior to slaughter.

Most of the three big pharmaceutical companies producing implants (Merck, Zoetis & Elanco) spend resources (time and money) explaining to producers and the general public about the safety of implants. They are so safe it is really very much a non-issue in my opinion.

It is too bad big business such as A&W in its recent marketing campaign tries to cast doubt on the subject. The fact is ranching is more sustainable with the use of implants among other things to assist in growth. A lot of countries, including many in the European Union, raise and slaughter intact bulls so there’s not the need to implant.

Many plant products we consume have much higher levels of natural estrogens, for example, than our implanted beef. We need to all take the next message forward to the consuming (urban and rural) public any time there is push back or total misconception from the ill-informed about the safety of implanted beef. Even some producers have this ill-conceived notion. Again unless calves are in some branded or natural program, 95 per cent of calves entering the feedlot are implanted immediately. This is again why A&W has had to go out of country to places such as Australia and the U.S. to get enough “no added hormone” products for its burgers. What they fail to explain is intact bulls produce many times the levels of hormones, than castrated animals. When implants are used in steers, we take out most of the hormones with the testicles and replace a low level in the ear.

Benefits the environment

From a green perspective, the reality is faster-growing cattle produce less greenhouse gas, require less land, eat less feed and drink less water over their lifetime so they leave a much smaller carbon footprint. If no cattle were implanted, dewormed or given other growth promoting technologies beef would cost much more to raise.

People have lots of hormones circulating naturally in their bodies and a lot of plants or even dairy products have multiple times more hormones than a meal-size portion of beef.

Implants give more of a consistent return than pretty well any other protocol we apply when raising cattle. More implants are also being developed with a delayed release that eliminates another pass through the chute to re-implant — a great labour-saving technology. Think of raising very healthy beef with the added knowledge implants are extremely safe so we can all help feed the hungry world with an excellent quality meat protein — Canadian beef.

About the author


Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.



Stories from our other publications