Antibody mechanisms implicated in digestive disturbances following ingestion of soya protein in calves and piglets
Barratt, M.E.; Strachan, P.J.; Porter, P.
Clinical and Experimental Immunology 31(2): 305-312
1978
ISSN/ISBN: 0009-9104 PMID: 565686 Document Number: 135790
Serum antibody responses to ingested aqueous alcohol-extracted soya proteins were studied in 30 pre-ruminant calves. Characterization of this antibody showed it to be predominantly a complement-fixing IgG1 precipitin. No evidence of tolerance was seen; previously sensitized calves responded to reintroduction of a soya diet with marked increases in antibody levels. The soya antigen was resistant to proteolysis and, to a lesser degree, to the microbial action of rumen fluid. Biopsy studies showed that the feeding of soya protein resulted in morphological disturbances to the villi and lamina propria of the intestine. Physiological studies by Thiry-Vella loop perfusion in the pig showed that soya protein solutions resulted in significant inhibition of flow rates. The effect was only observed after previous sensitization with the soya antigen. This study shows the necessity of applying immunological criteria to the quality control of soya bean processing to ensure that the sensitizing agent is eliminated and the nutritional qualities of soya protein concentrates are optimized.