Growth promoting implants for pasture cattle

A variety of trade names and combination of growth promoting impacts have been used over the past 50 years according to Eldon Cole, a livestock specialist with University of Missouri Extension.

"Implants are one of the most cost-effective technologies available to beef producers. Not only do they boost gains, they improve feed efficiency and increase protein deposition," said Cole.

Research studies support that when used, growth promoting impacts can actually result in a seven percent overall reduction in the cost to produce beef.

Cole acknowledges that some consumers question the safety of implants.

"The implants on the market do not have harvest withdrawal times. This indicates they have been thoroughly studied by the Food and Drug Administration for safety," said Cole.

An implant is actually a small pellet or group of pellets that are placed under the skin on the backside of the animal's ear. One product even comes in liquid form.

The growth promoting compound is released slowly over varying periods of time ranging from 60 to 200 days or more. Implants are designed for nursing calves, steers and heifers on pasture and in feedlot situations.

"The use of implants is greatest in feedlots where its use approaches 90 percent. The exception is those lots that feed for the all-natural market," said Cole.

Use among stocker/backgrounders approaches the level seen in feedlots while the cow-calf sector has fewer than 20 percent of the operations using the tool.

Implants come in a variety of price ranges. Several are available for under $1 per head while the longer acting products will be in the $2.50 range when larger volumes are purchased.

Gain responses depend on the animal's rate of gain.

"Typically, we see an extra 15 to 20 pounds on the implanted calf at weaning. Stocker cattle, provided the forage supply is good, may even respond with a 10 to 15 percent improvement in daily gain," said Cole.

Implants on nursing calves are given between 2 and 4 months of age.

"Some are approved for heifer calves, but if they are destined for breeding stock, some owners will only implant the steer calves," said Cole.

If heifers are implanted, only approved products should be used one time between one month of age and weaning time.

Bull calves often are left intact to reap greater gains from their natural hormone output.

"Research indicates that castration early in life, along with a growth promotant, will essentially equalize weight gains for the bull and implanted steer at weaning," said Cole.

Early castration reduces the overall stress on the calf. Bull calves are discounted at the market and at some point will suffer more from late castration than they would have if castrated as nursing calves.

For more information, contact any of the MU Extension livestock specialists in southwest Missouri.