Source: Michael Fielding, MEATINGPLACE, 8/26/15

Belgian researchers have found that the meat quality of immunocastrated pigs improves when producers extend the length of time between the second injection and slaughter.

When the second injection is administered at six weeks prior to slaughter instead of four weeks, both intramuscular fat and slaughter weight improved, and there was no measurable impact on the carcass leanness, lead researcher Marijke Aluwé told scientists gathered at the 61st annual International Congress of Meat Science & Technology (ICoMST) conference here, 265 miles south of Paris.

An innovative technology, immunocastration has grown in popularity across Europe as an alternative to physical castration. It is designed to allow pigs to remain intact while removing boar taint. Administered via two injections, the drug that causes immunocastration leaves the pigs intact while working with the immune system to shut down the production of the compounds that cause boar taint.

The first dose is administered no earlier than 9 weeks of age (when the hypothalamus and pituitary begin to mount a respone to it). That priming dose triggers the body’s memory system to create the onslaught of antigens when the second dose is administered. The second dose typically is administered 4-6 weeks prior to slaughter.

The pig’s body identifies the foreign protein as an antigen. Various types of cells respond, triggering the production of antibodies. The immune system responds by creating an antibody against GnRF — halting the release of LH and FSH, and thereby preventing the release of testosterone and the subsequent release of skatole and androstenone.

The end result is a castrated pig that remains intact, nearly eliminating boar taint altogether while maintaining the benefits of an otherwise non-castrated pig: better feed conversion and improved average daily gain.

In the study, conducted at the Institute for Agricultural and Fisheries Research in Belgium, researchers studied 180 pigs, administering the second dose at both four weeks and six weeks prior to slaughter.

“There is some potential for improved meat quality,” she said of the earlier second injection, adding that boar taint — the impetus for developing the technology in the first place — was not detected.

For more stories, go to www.meatingplace.com.