Pfizer Animal Health announced Thursday that the U.S. Food and Drug Administration (FDA) has approved Improvest® (gonadotropin releasing factor-diphtheria toxoid conjugate). Farmers have the option to use this safe and effective veterinary prescription product for temporary immunological castration and reduction of boar taint in intact male pigs intended for pork.
Improvest is a protein compound that uses the pig's own immune system to provide the same effect as surgical castration, but much later in the male pig's life.
By eliminating the need for surgical castration, the animal grows with all the inherent advantages of intact males until the second dose. Studies confirm that intact male pigs eat less feed and produce more meat, increasing feed efficiency by 6 to 10 percent,1 along with a typical improvement of 2 to 2.5 percent higher cutout yield.2 And, since male pigs given Improvest are not surgically castrated, the risk of infection or death is eliminated, decreasing mortality by 1.6 percent.3
Because intact male pigs eat less feed and produce more pork there is potential for an incremental reduction in the carbon footprint by as much as 3.6 percent (measured in CO2 equivalent per kilogram of pig live weight) versus barrows.4
"Improvest creates an opportunity to capture more value from male pigs that didn't exist until now," said Jim Bradford, DVM, director, Team Lead, Improvest, Pfizer Animal Health. "Male pigs are given Improvest later in the finishing phase to manage boar taint, so they're able to grow to their full intact male potential, and do it more efficiently."
This technology is approved in 58 other countries around the world, including the European Union, Australia and Japan, under the related global brand, Improvac®.
Pigs are given Improvest via injection. The first dose primes the system and should be administered no earlier than nine weeks of age. The second dose should be administered at least four weeks after the priming dose.
Pigs should be sent to market no earlier than four weeks after the second dose of Improvest to allow adequate time for reduction in the compounds responsible for off odor in pork. Marketing pigs on the Improvest program more than eight weeks after the second dose may increase the risk of off odor in pork. Only trained, certified technicians will be permitted to administer the product as part of the quality assurance program.
As the product is gradually introduced, Pfizer Animal Health will work with veterinarians and their producer clients to help them adopt new nutritional guidelines and best handling practices to optimize growth for intact males.
"This gradual approach provides the time needed to ensure a coordinated food chain effort, and gives processors and packers time to integrate and optimize this into their systems, as well," Bradford said. "We want to ensure the best Improvest program experience for everyone - from farmers to meat packers, processors and retailers, and, ultimately, to consumers."
Important Safety Information
Improvest should not be used with female pigs, barrows or male pigs intended for breeding. Special care should be taken to avoid accidental self injection during administration of Improvest. Accidental self injection could negatively affect reproductive physiology of both men and women. Therefore, pregnant women should not administer Improvest and women of childbearing age, as well as men, should exercise extreme caution when administering the product. There is no risk, however, of these effects on an individual who consumes pork from pigs given Improvest.
Additional product information will be available at www.PfizerPork.com/IMPROVEST.
1. MacKinnon, J and Pearce, M. Improvac (Pfizer Animal Health): an immunological product for the control of boar taint in male pigs. II. Practical application in pig production and potential production benefits. The Pig Journal. 2007, 59:68-90.
2. Boler D, Kutzler L, Meeuwse D, et al. Effects of increasing lysine levels on carcass composition and cutting yields of immunologically castrated male pigs. J Ani Sci 2011; doi:10.2527/jas.2010-3640.
3. Allison J, Pearce M, Brock F, Crane J. A comparison of mortality (animal withdrawal) rates in male fattening pigs reared using either physical castration or vaccination with Improvac®as the method to reduce boar taint. Proc. 21st IPVS Congress, Vancouver, Canada. July 18-21 2010, pp. 1139.
4. The International EPD System. Improvac. Available at: http://gryphon.environdec.com/data/files/6/7831/epd261.pdf. Accessed on March 9, 2011