Allergens affect pigs by contributing to increased morbidity and decreased efficiencies of gain. The allergens found in feed ingredients like soy can be genetically removed from the soybean, thereby reducing negative effects of allergenic response. However, a quantitative allergenicity model in swine is needed as a decision tool for making appropriate changes in soy seed composition and for improving formulation of feed ingredients. To address this potential in swine nutrition, we are working through a multi-year, multi-institution project to thoroughly research the benefits of removing soy-based allergens in the swine diet.
The objectives are to genetically select a pig population that reproducibly exhibits hypersensitivity to soy products, to produce antibodies that specifically recognize swine immunoglobulin IgE, levels which indicate allergic response within blood serum and to demonstrate a quantitative assay for allergenic response using swine IgE.
During the first year of the project, which was completed May 31, 2007, great progress was made in identifying allergenic responses in piglets when challenged with a potential allergen and demonstrated clear differentiation between litters. The ability to clearly determine an allergic response is key in testing a feedstuff that has allergen-causing components removed to ensure that health benefits can be observed once the feed has
been improved.
Results so far suggest that original expectations may be exceeded. Related work within USDA has demonstrated the ability to successfully eliminate most of the major seed storage proteins without detriment to seed development and germination. This opens the way to make large-scale changes in seed composition for elimination of antigenic proteins as well as beneficial changes that influence seed nutritional quality. Moreover, changes in seed composition necessary for validating the swine model have been demonstrated to be possible.
The first year of this three-year project has been completed, and more useful information will be forthcoming during the next few months. Establishment of a credible model for evaluation of hypersensitivity to soy is a necessary step toward the development of strategies that will help sustain domestic swine production and protect long-term demand for U.S. soy meal. The ability to identify desirable genes involved in the pig immune response will enable selection of genetic lines that do not exhibit hypersensitivity after early weaning. Healthier pigs should improve productivity and reduce production costs. Enhancement of soy protein quality through genetic modification to reduce, replace or eliminate proteins that mediate immune responses will provide meal with improved digestibility and nutritional value while enhancing the use of soy meal to replace fish meal and other ingredients in pig rations.
This project is jointly funded by the National Pork Board, the United Soybean Board and QUALISOY in cooperation with USDA-ARS. For further information, please contact Tracy Barfield at the United Soybean Board (Email: [email protected]/Phone: (314) 579-1580), or Rich Wilson (Email: [email protected] /Phone: 919-834-8695)
