Allergens affect pigs by contributing to increased morbidity and decreased efficiencies of gain. The allergens found in feed ingredients, like soy that show allergenic response can be isolated and targeted for removal from the soybean, thereby reducing negative effects of allergenic response. The potential for developing an allergenicity model in swine and using that model to change input feed ingredients means great future potential for the swine industry. To address this potential in swine nutrition we are working through a multi-year, multi-institution project to thoroughly research the benefits or removing soy based allergens in the swine diet.

The objectives of this project are to genetically select a pig population that reproducibly exhibits hypersensitivity to soy products, to produce antibodies that specifically recognize swine IgE, and to demonstrate a quantitative assay for allergenic response using swine IgE.

During the second year of the project, which completed May 31, 2008 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 you can observe the health benefits once the feed has been improved.

Results so far suggest that original expectations may be exceeded. Related within USDA have 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 and 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.

We have completed the second year of this 3-year project, and more useful information will be coming forth 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 both 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.