For Austin, MN, producer Gehl Mittelsted, Paylean is putting more pounds of lean on pigs and reducing backfat by nearly 5%. As a result, substantially more pigs are hitting the “red box” — an area on his packer's grid that pays more than 100% of the base contract price.

Mittelsted's packer, Hormel Foods, pays according to 10th rib backfat, but fat isn't his main concern. “My challenge is to take pigs heavier and see if they'll hold. We're targeting the packer's sweet spot to get a higher percentage of base. That's what Paylean does for us,” he says.

For the sake of simplicity, pigs receive 6.75 g./ton of Paylean for 21 days. Mittelsted was feeding a step-up ration of 4.5 to 9 g./ton, but bins are easier to manage by averaging the levels at 6.75 g./ton, he explains. Barrows receive the Paylean ration at Week 16, about seven days sooner than gilts. All of his pigs, over 100,000 head annually, are finished on contract and all receive Paylean.

How Paylean Works

The brand name for ractopamine hydrochloride, Paylean is a feed ingredient that directs nutrients to produce muscle instead of fat. Elanco Animal Health, the maker of Paylean, estimates 40% of U.S. hogs are fed the product. Ractopamine is one of a group of compounds called beta-adrenergic agonists and is the first of its class to be FDA-approved for swine.

Beta receptors, located on the surface of muscle cells, bind with ractopamine to alter the ratio of muscle to fat. The response can be phenomenal the first week, but over a period of time, these receptors begin to lose their ability to be stimulated, which is why growth rate characteristics start to de-cline after four weeks.

The step-up program endorsed by scientists attempts to avoid desensitization of these receptors by giving pigs a boost of ractopamine two weeks after the first feeding. Ideally, the first marketing cut is made after pigs have been on Paylean for a week, with the majority of pigs on ractopamine three to four weeks prior to slaughter.

Measurements Miss Lean

Purdue University geneticist Allan Schinckel, who has done extensive growth modeling with ractopamine, says the increase in lean gain is by far the primary effect of Paylean. “Ractopamine can add up to 10 lb. of lean to a carcass in four weeks, causing a larger increase in loineye size and muscle mass and a smaller change in backfat than expected,” says Schinckel.

The distribution of lean throughout the carcass also changes. Relatively larger increases in the lean content of the ham and belly are seen — all cuts that evade optical probes or other carcass measurements.

Schinckel's data shows common loin depth and backfat measurements taken by the optical probe, or Fat-O-Meater, pick up 50 to 55% of the increased lean caused by ractopamine. Ultrasound measurements of loineye area and backfat fall in the 60-65% range, while last rib backfat measurements detect only 15 to 20% of the increased lean.

The TOBEC machine, used to measure whole body lean, will pick up over 75% of the lean response to ractopamine, Schinckel says. When combined with fat depth, the TOBEC estimate is even better.

What that means, explains Schinckel, is that a 2% increase in lean as measured by an optical probe is really twice that amount, or 4%. “It's a drastic underestimation,” he says. “The optical probe loin depth measurement used by many packers isn't a very exact measurement of carcass muscle mass. Ractopamine increases loin depth more than it reduces backfat, so it's inherent that optical probe measurements will be biased against Paylean's full value.

“Any payment system that puts greater emphasis on a measure of muscle mass will be more accurate and less biased,” he continues. Schinckel says a measure of ham muscle would provide a more accurate estimate of the full impact of ractopamine.

One problem with underestimating lean accretion is it tends to skew lysine levels, he adds. If lysine levels aren't high enough, pigs won't receive optimal Paylean response. It is important to balance for all amino acids, keeping ratios in sync with lysine.

Paylean's Payback

Mittelsted's nutritionist, John Goihl, with Agri Nutrition Services, Shakopee, MN, boosts lysine levels 0.25% for barrows and gilts. To get the added lysine and other amino acids, corn is replaced with soybean meal. Goihl says Paylean is costing Mittelsted about $2/pig, figuring the added soybean meal and Paylean at $25/lb. and a per-pig feed consumption for approximately 150 lb. There are about 9 grams of active ingredient in a pound.

Goihl considers Paylean a management tool specific to each grower. “Mittelsted is evaluating Paylean as most should — the added premium for a higher percentage of pigs in the red box,” he points out. “Improvement in gain and feed efficiency offsets the added diet costs. It's really a carcass modifier and that's where Paylean makes money for him.”

Two types of genetics, Monsanto Choice Genetics and PIC, are finished at Mittelsted's contract farms. Cutout figures for both genotypes consistently garner 105%-plus over base with lower backfat. Close to 90% hit the red box, which means a hefty quarterly bonus. Pigs falling in the 81-85% range earn $1.50/head and pigs over 85% earn $2/head.

“Paylean took the DeKalb (Monsan-to) pigs from a No. 4, just outside the red box, to a No. 3, a reduction that was less than a tenth of an inch of backfat,” recalls Mittelsted. “That was all we needed to get into the red box. But Paylean isn't for everyone. If you're way out of the box, it won't get you there.”

Packer comparison information over a recent 90-day time period shows Mittelsted's pigs averaged 105.27% over base, while the top 25% of all pigs sold to his packer during the same time period earned 104.57% of base. His pigs averaged 0.78 in. of backfat, compared to 0.84 in. for the top 25%. Another interesting figure was the “% Too Fat”. Only 2.6% of Mittelsted's Paylean-fed pigs were too fat, vs. 8.2% of the top 25%. And 87% landed in the red box vs. 84.5% for the latter group.

“In a nutshell, that's what Paylean can do,” he says. “We're getting a 7-9 lb. heavier carcass. That's what we're after, the same pig, only heavier. Paylean fits our genetics well.”

Tough Logistics

In contrast, Howard Hill, DVM, director of operations at Iowa Select Farms, Ames, IA, quit using Paylean about six months ago. “We had some genetics that were a little fatter, so we were using Paylean at the request of a particular packer. But label issues and logistical problems with feeding it a short time made it too difficult to implement into a large system,” he says.

Hill feels the only economic benefit to feeding Paylean in their system is the 5 to 8 lb. of increased body weight — something they can replicate by leaving pigs on feed for three extra days. That's assuming space is not a limiting factor, he adds.

‘Slows’ an Issue

One large midwestern packer believes the Paylean concept is a win-win situation because it improves pig performance and provides a more heavily muscled carcass. Their system of evaluating loin depth and fat depth can pick up the effects of Paylean, and that means the grade premium will more than offset the cost of the product with a heavier pig. “Producers using Paylean could get a higher premium than they might without using it,” states a spokesman for the packer.

One of the possible pitfalls of feeding Paylean, he adds, may be “slows” — pigs that seem to run out of energy and walk slowly or lie down. He prefers to avoid the term “downers,” since this does not involve hogs that are injured or sick. Some producers attribute the incidence of “slows” to Paylean.

“Like any new technology, Paylean usage needs to be fine-tuned with more focused management and better handling. Our producers are experimenting with different amounts in the diet to provide growth rate changes, as well as a desirable carcass with minimal slow animals,” he explains.

Taste-Tested Loins

Do the larger pork chops from Paylean-fed pigs taste as good? Results of a joint project on carcass and meat quality at Ohio State University and Iowa State University help answer that question.

Three genetic lines, all fed the 9-gram level, were used in the study: Berkshire, a fatter, slower-growing line with extremely good meat quality traits; Duroc, a popular terminal sire breed good in lean gain and quality; and a typical, high-lean commercial line for cutability and performance.

Differences were observed between genetic lines for quality and sensory traits, with Berkshires being superior. Berkshires fed ractopamine, however, had a lower percentage of intramuscular fat than control counterparts not fed ractopamine.

Paylean-fed pigs showed a trend toward lower backfat in the study, with Berkshires as the exception. And, all three lines had a significant increase in loineye area.

The usual quality traits — water-holding capacity, palatability, pH, color and marbling — were measured. A trained sensory panel assessed juiciness, tenderness and chewiness, and concluded that ractopamine had no effect on the quality attributes.

“In a nutshell, can we change the carcass without affecting quality? Yes,” replies Steve Moeller, Ohio State extension swine specialist and co-author of the study. Results of the project were reported at the recent American Society of Animal Science Association annual meeting.

Fewer Tail-enders

One other area that can benefit from Paylean are the tail-enders. “Paylean can narrow the time frame between the first and last group by helping lightweight pigs catch up,” points out University of Missouri agricultural economist Ron Plain. “And as packers adjust their weight brackets higher, it makes Paylean more attractive.”

Average market weights have moved up about a pound per year in the last 40 years to today's 260-lb. average, he notes. “That's a problem for Paylean, since the label says feed to 240 lb. when it should go to 320 lb. I think we'll see modest Paylean usage until FDA gets around to approving new label requirements.”

Debra Neutkens is a freelance writer based in White Bear Lake, MN.

Handle with Care (and No Prods)

Downers are an issue with the industry. Also called “slows,” these are the pigs that become fatigued for no apparent reason and refuse to get up and walk. Many factors can influence downers, but it seems more prevalent in heavily muscled pigs. The presence of the stress gene or use of ractopamine hydrochloride (Paylean) is commonly blamed.

Elanco Animal Health, the maker of Paylean, is looking for reasons why. “We decided to study the physiology of downer pigs,” says David Anderson, senior research scientist with Elanco. Pigs were taken from a commercial midwestern plant that was processing 14,000 head/day over a three-day period. “We evaluated things such as muscle tremors and vocalization, measured rectal temperatures, collected tissues and did blood tests — in Paylean and non-Paylean-fed pigs. What we found was evidence of metabolic acidosis.

“The bottom line is downer pigs have a pH that is 7.1, which is very low. A normal pH is 7.36 to 7.44. The most important factor contributing to metabolic acidosis is handling,” he adds.

Elanco took the study a step further, developing a model for handling at-risk pigs and identifying factors associated with downers. “Our recommendation is to treat pigs as gently as possible and reduce use of electric prods,” says Anderson.

Minnesota producer Gehl Mittelsted feeds Paylean to thousands of pigs and agrees that handling is a big issue. “Paylean pigs cannot be pushed. They're like body builders; they walk slower and stiffer; they take twice as long to load.”

Mittelsted works with his truckers to get pigs to the dock in good shape. “Pigs aren't crowded on the truck — 185 head are shipped per load vs. 200 — and we make sure everything walks off,” he says.

Elanco also studied the effects of feeding a buffer shortly before slaughter to offset lactic acid production in downer pigs, notes Anderson. The added electrolyte, in this case sodium bicarbonate, reduced downer rates by half.

National Institute for Animal Agriculture offers these additional tips to minimize stress during transport:

  • Prepare pigs for moving and transport by walking pens 1 min./pen each day or 5 min. each week.

  • Withhold feed 4-6 hours before loading or 12-18 hours before slaughter.

  • Minimal electroshock should be used and only as a last resort.

  • Equalize lighting and temperature and open curtains 15 min. prior to loading.

  • Move pigs in small groups and avoid sharp turns and bunching.

  • Do not overload.

  • Once loaded, leave immediately for the packing plant.
    Debra Neutkens