You can expect hormone implants to increase the rate of gain in yearling cattle on grass by 10 to 20%, says Kenneth Olson, South Dakota State University professor Extension beef specialist.

But you have a lot of implants to choose from, and you’ll want to pick the right ones for your situation.

The top things Olson says to consider are:

Yearling cattle can gain 10-20% more on grass.

Implant potency. Implants are generally grouped as low, moderate, and high potency. You need to match up the potency with the energy level in the diet. High potency implants are for feedlot cattle. Low- and moderate potency implants are best for grazing cattle. In from late spring through mid-summer, when green grass energy contest is highest, moderate potency implants are okay for stocker cattle. From mid-summer through fall, when energy levels in grasses are declining, low-potency implants are best.

Implant life. If the intent is to graze from mid-May to early October (about 135 days), many implant products pay out in 100 days or less.

This leaves you with three possible options for the remainder of the grazing season:

1) Gather cattle and re-implant. This may be the least desirable option because it involves the cost, time, and effort to buy another round of implants and then gather and work the cattle. Also, this is a period of declining gains in cattle, so the expected response to the re-implant will decline in direct proportion and the possibility of negative impact on marbling exists unless a low-dose implant is used. And the implant may last beyond the grazing period. "This is ineffective from the grazing standpoint and may interfere with subsequent feedlot implant goals," he said.

2) Use an extended-life implant. Some of these can have a life as long as 400 days. "This option ensures active ingredient payout at least as long as the grazing season," Olson says.

3) Leave the cattle without implant coverage late in the grazing period. "This may be the best option because of declining forage energy content and the potential negative effect on marbling fat deposition during late summer and fall," Olson says.

Implant economics
Assume you start the grazing season with some 600-pound yearling steers intended to graze for 130 days.

During the first 100 days of the grazing season we would expect 2.5 pounds of average daily gain (ADG) without implants.

You choose a moderate-potency implant that is expected to improve ADG by 15% over about 100 days. The enhanced ADG will be 2.88 pounds leading to an additional 38 pounds of growth.

Using the Beef Basis Forecasting Tool, found at www.beefbasis.com, the projected sale value in late September of this additional gain will be $51.77 per steer.

If the implant costs $1.35 per head, the return on investment is projected at 38:1, assuming steers are implanted when being worked before turnout to grass so there are no additional costs of implanting.

An alternative to implanting stocker cattle would be to enroll the cattle in a non-hormone treated cattle program that would provide a price premium for leaving them un-implanted.

"In this case, the non-hormone treated cattle premium would have to be greater than the $50 net value from using implants," he says.

Source: SDSU