There should be little surprise left about the performance gains possible by using implants in the stocker pasture. They've been around for decades, and the primary ingredients used in many implants — progesterone, estradiol benzonate and trenbolone acetate — remain unchanged.

As Ted McCollum, III, a Texas A&M University (TAMU) beef cattle specialist points out, “Of all the management practices available to cow-calf and stocker cattle producers, implanting suckling calves and stocker cattle offers one of the highest benefit-to-cost ratios.”

For stocker perspective, McCollum explains, “A single implant (in stocker cattle) will increase weight gain 8-18% or 15-40 lbs. during the grazing season. If the grazing season is more than 100-120 days and the plane of nutrition is adequate, re-implanting or using an implant with a longer release period stimulates additional weight gain.”

Likewise, a study conducted by Kansas State University (KSU) in 1997 provides a snapshot of stocker implant possibilities (Table 1). The bottom line of a number of trials included in the study was that stocker steers and heifers receiving an estradiol/progesterone implant and grazed for 150 days gained 33.3 lbs. more than unimplanted peers, at a cost of 96¢/head.

Given the substantial and predictable return on investment, most stocker cattle likely receive implants. Based on market share data, Pete Anderson, VetLife director of technical services, estimates, “Virtually all feedyard cattle are implanted, about 25-30% of suckling calves receive them, and stocker cattle come somewhere in between. We'd say approximately 60-70% of stockers get implanted.”

Fear and perception

That means there are still 30-40% of stocker cattle that aren't implanted. The reasons, Anderson says, range from solid logic to fears induced by perception.

As for the logical reasons, one is that a growing number of stockers — though a mass minority — are destined for natural beef programs that disqualify cattle receiving growth promotants. But, more often, he believes stockers aren't implanted simply because they're run in situations where the lack of facilities makes the management practice impractical or impossible.

Still other producers don't implant their stockers because they fear buyers will pay lower prices for previously implanted feeders. The theory goes that cattle implanted in the stocker pasture will perform less than they otherwise would once in the feedlot. While the fear of discounts is understandable, the reality of this particular concern may not hold much water.

While there's little question buyers will use the opposite of what you have or don't have as bargaining leverage in negotiations, Anderson points to a study conducted a couple of years ago. The study found no average price differences between implanted and non-implanted cattle sold at auction; implant history being conveyed to buyers. Apparently, buyers take such claims from the sale block with a grain of salt.

But there's little scientific evidence to support the view that previous implants dampen subsequent feedlot gain. Anderson says 80% of the research data examining differences in feedlot performance between cattle implanted or not implanted before coming to the yard show no difference.

A smaller percentage of studies, however, indicate previous implants negatively affect subsequent feedyard performance. But Anderson suspects it's perhaps partly due to a failure to either match implant products to the class of cattle and performance level, or to coordinate the timing between implants administered in the stocker enterprise and in the feedlot.

“If we knew exactly what happened to stocker cattle on grass, in some instances we would probably wait 30-40 days to implant them in the feedlot,” he says. In other words, stacking incompatible products on top of one another could contribute to diminished implant returns found in some studies.

“It's my view that the more aligned that stockers can become with feedlots, and the more aligned feedlots can become with stockers, then more trade of reliable information can be developed and the better off both sides will be,” Anderson says.

Keep current on technology

Finally, one reason some folks ignore implants is because they tried them before and believe they received no benefit. It's possible, but given the abundance of data suggesting gains should be expected when cattle are receiving enough nutrition, it may be more perception than reality, he says.

For instance, it can be tough to see 15 lbs. of extra gain in cattle, especially if all of them have been implanted and there's no point of comparison.

In addition to stocker cattle operators who forego implants altogether, Anderson believes others leave pounds on the table by using the wrong product at the wrong time in the wrong situation, or by being too conservative in their implant strategies.

Of course, Anderson says, there are situations when implanting stockers makes little sense. An example is when cattle are parked on grass — warehoused — with no intent of them gaining weight. Or, when the cattle aren't receiving adequate nutrition to utilize implant ingredients.

“Our rule of thumb is if the cattle aren't gaining at least ¾ lb./day, you won't see much benefit to using implants,” he says.

As for playing the game too safe, Anderson explains, “Generally, stocker operators err on the conservative side. I see them use products with shorter duration and more moderate efficacy than they could use in a particular situation.”

Incidentally, McCollum explains, “An implant releases active ingredient or ‘pays out’ for 70-400 days depending on the implant. Although the implant releases active compound over an extended period, at some point the quantity of active ingredient released declines to a level that does not stimulate performance adequately.

“As a rule of thumb, the window to re-implant cattle is about 30 days less than the estimated payout. So if an implant has a payout of 100-140 days, administer another implant at 70-100 days if you want to maintain circulating levels of the active compounds,” McCollum says.

Part of implant conservatism may stem from force of habit. Based on the success with using a particular product in the past, stocker operators may continue using it with each new set of cattle. That's even though a product containing a new presentation of active ingredients might be better suited.

With stocker seasons ranging from approximately 30-200 days, Anderson says there are product choices covering the gamut of payout windows described by McCollum. “You want to match the product choice and dosage level to the level of projected gain performance,” Anderson says.

Obviously, he says producers need to remember that some implants are labeled for use in only steers or heifers, while some can be used in both.

Even with so many different products available for tailoring to specific situations, McCollum believes, “Selection of an implant is less critical than the decision of whether to implant or not.”

Outside of inadequate nutrition or goals that don't include gain, Anderson says, “If it's the right program, there will be more benefit than not.”

For more stocker production information visit beef stocker USA www.beefstockerusa.org

Table 1. Summary of stocker implant research trials*

No Implant Implanted
Average Daily Gain (lbs./day) 1.48 1.70
Total Gain-150 Days (lbs.) 222 255
End Weight (lbs.) 722.0 755.3
*Summary represents both steers and heifers (500-lb. starting weight) grazed 150 days; implanted cattle received a combination estradiol/progesterone product.
Source: Kansas State University