‘We’ve almost forgotten that boars just perform better’
Larry Rueff, DVM, is a big believer in immunocastration. Ever since the swine veterinarian from Greensburg, IN, stopped physically castrating some of his pigs 4 years ago, and started using a protein compound that works like an immunization to block boar taint, he’s noticed significant improvements in growth and feed efficiency.
He does want to make one thing clear, though.
“Immunocastration is not the reason the performance is so good,” he stresses.
“It solves the pain-mitigation and infection issues around physical castration. But what it’s allowing the pig to do is to just be a boar. And that pig just performs better than if he had been physically castrated.”
‘Let boars be boars’
“Let boars be boars” is a favorite expression of the veterinarian, who has run 13 groups of immunocastrated pigs through his wean-to-finish facility. Compared to barrows with the same genetics, the immunocastrated pigs he rears consistently demonstrate a 14% to 15% improvement in feed conversion — figures he acknowledges sound like “liar’s numbers.” In reality, however, he says they’re normal for boars.
“I think as an industry we’ve almost forgotten that boars just perform better,” he says. “And so when we use this product, we just get performance levels that most people are unaccustomed to.”
Carcasses from immunocastrated pigs tend to be leaner than those of conventional barrows, Rueff notes, but he says he’s had “no complaints” from packers in the 4 years since he started using the castration alternative. Another benefit he has observed in immunocastrated pigs is that they’re much less aggressive than sexually mature boars — a difference that he says visitors to his barn notice immediately.
Slow uptake in US
Despite these benefits, immunocastration has been slow to catch on among US pork producers, even as its use has steadily increased in Europe, South America, Asia and Australia. Rueff attributes this mainly to a lack of understanding as to how the product works among packers and retailers, who are concerned with how consumers may respond.
“They think hormones. They think of something that would make the pork unsafe. These ideas…are confusing in a lot of areas of food today,” Rueff explains.
“All immunocastration does is block the physiologic process that allows [the compounds responsible for boar taint, androstenone and skatole] to be made…just like the immune system reacts when we vaccinate for mycoplasma or circovirus. We’re just using the body’s natural immune system to turn things off.”