Bovis ISSN 2398-2993

Soybean toxicity

Synonym(s): Soybean meal or overconsumption, consumption of under-processed of soybean product, soyabean, soya bean, Glycine max

Contributor(s): Nicola Bates , Didier Raboisson

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Introduction

  • Cause: ingestion of unprocessed or insufficiently processed soybeans or overconsumption of soybean, or soy bean meal. 
  • Signs: reduced growth, possible reproductive failure from unprocessed or insufficiently processed soybeans; neurological signs from overconsumption.         
  • Diagnosis: based on history and clinical signs. 
  • Treatment: dietary change after unprocessed or insufficiently processed soybeans; rumenotomy, cold water and acetic acid for urea toxicosis from overconsumption.
  • Prognosis: good for effects from unprocessed or insufficiently processed soybeans; depends on the severity of signs after overconsumption.

Pathogenesis

Etiology

  • Soybean (Glycine max) is a major legume crop (native to East Asia), grown for its protein- and oil-rich seeds.
  • The soybean harvest is mostly for oil extraction and the by-products (primarily soybean meal) are further processed to animal feed, human food and industrial products.

Predisposing factors

Unprocessed or insufficiently processed soybean

  • Chronic exposure.

Overconsumption of soybeans or soybean products

  • Accidental free access or too much in the ration.

Pathophysiology

Unprocessed or insufficiently processed soybean

  • Soybeans contain antinutritive factors (see Table: A summary of the antinutritive factors in soybeans) and require processing to make them suitable for animal feed.
  • The protease inhibitors and lectins are the most important antinutritive factors in soybeans.
    • Protease inhibitors cause markedly increased secretion of pancreatic enzymes (and pancreatic hypertrophy/hyperplasia) overwhelming the normal digestive capacity of the gastrointestinal tract and resulting in a pancreatogenous protein-losing enteropathy in adult cattle.
    • Lectins bind to glycoprotein receptors in intestinal epithelium and inhibit growth by interfering with the absorption of nutrients.
  • Other antinutritive factors in soybeans are of less significance and include goitrogens, tannins, phytoestrogens, flatus‐producing oligosaccharides, phytic acid and saponins. There are also other diverse but ill‐defined factors that appear to increase the requirements for vitamins A, B12, D and E.
  • Different cultivars of soybean vary in the content of the antinutritive factors.
  • Unprocessed soybean can inhibit growth, depress metabolizable energy and fat absorption, reduce digestibility, cause pancreatic hyperplasia/hypertrophy, stimulate hypo- and hypersecretion of pancreatic enzymes and reduce amino acid, vitamin and mineral availability.
  • Growth inhibition from chronic feeding of raw soybean products is reversible.
  • It is not yet clear whether there is a dose effect effect for soybean toxicity, but the author would hypothesize that the quantity of beans/meal ingested would be significant. However, the concentration of antinutritive factors between plants does vary, as will duration of exposure and thus there are other variables to consider.

Overconsumption of soybeans or soybean products

  • Ingestion of a large volume of soybeans or soybean meal can result in ammonia accumulation due to continued ammonia production, decreased carbohydrate fermentation and overwhelming of hepatic detoxication capacity.
  • In experimental cases involving soybean meal there were clinical signs and biochemical changes after ingestion of 2% of body weight (20 g/kg).

Timecourse

Unprocessed or insufficiently processed soybean

  • Variable; depends on the amount of the ration, other forage given, age and duration of exposure.

Overconsumption of soybeans or soybean products

  • Onset of clinical signs is approximately 4-36 hours, and varies depending on the quantity of soybeans or soybean product consumed.
    • Experimental data show that acute soy bean meal doses such as 1%BW did not induce clinical signs but did produce biochemical modifications. In the study in question, clinical signs were observed in animals that had consumed  ≥ 2% BW dose of soybean meal.
  • Clinical signs in animals in the same herd can be very variable.
  • Recovery may take several days, depending on the severity of poisoning.

Epidemiology

Unprocessed or insufficiently processed soybean

  • There is no information on the epidemiology of adverse effects from ingestion of raw soybean; most information is derived from experimental studies.

Overconsumption of soybeans or soybean products

  • There are occasional reports of overconsumption of soybean products, but it is rarely reported in the literature.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Müller D R, Soukup S T, Kurrat A, Liu X, Schmicke M, Xie M Y, Kulling S E, Diel P (2016) Neonatal isoflavone exposure interferes with the reproductive system of female Wistar rats. Toxicol Lett 262, 39-48 PubMed.
  • Raboisson D, Ferrières A, Nicot MC, Enjalbert F, Schelcher F (2013) Clinical and biochemical consequences of soybean meal intoxication in cattle. Vet Rec 172(20), 529 PubMed.   
  • Raboisson D, Ferrières A, Nicot MC, Enjalbert F, Schelcher F (2012) Experimental soybean meal intoxication in cattle. J Vet Intern Med 26(2), 393-401 PubMed.
  • Woclawek-Potocka I, Bah M M, Korzekwa A, Piskula M K, Wiczkowski W, Depta A, Skarzynski D J (2005) Soybean-derived phytoestrogens regulate prostaglandin secretion in endometrium during cattle estrous cycle and early pregnancy. Exp Biol Med 230(3), 189-199.
  • Beckers-Ritt A B, Mulinari F, Vasconcelos I M, Carlini C R (2004) Antinutritional and/or toxic factors in soybean (Glycine max (L) Merril) seeds: comparison of different cultivars adapted to the southern region of Brazil. J Sci Food Agric 84, 263-270.
  • Doerge D R, Sheehan D M (2002) Goitrogenic and estrogenic activity of soy isoflavones. Environ Health Perspect 110(Suppl 3), 349-353.
  • Lallès J P, Duvaux-Ponter C, Sissons J W, Toullec R (1998) Small intestinal motility disorders in preruminant calves chronically fed a diet based on antigenic soya: characterization and possible mediators. Vet Res 29(1), 59-72 PubMed.
  • Eweedah N, Gundel J, Mátrai T (1997) Protein degradability, amino acid composition, trypsin inhibitor and urease activity of raw and heat-treated fullfat soybean. Arch Anim Nutr 50, 361-367.
  • Lallès J P, Dréau D, Salmon H, Toullec R (1996) Identification of soyabean allergens and immune mechanisms of dietary sensitivities in preruminant calves. Res Vet Sci 60(2), 111-116.
  • Liener I E (1994) Implications of antinutritional components in soybean foods. Crit Rev Food Sci Nutr 34(1), 31-67.
  • Grant G (1989) Anti-nutritional effects of soyabean: a review. Prog Food Nutr Sci 13(3-4), 317-48.
  • Odani S, Koide T, Ono T, Seto Y, Tanaka T (1987) Soybean hydrophobic protein. Isolation, partial characterization and the complete primary structure. Eur J Biochem 162, 485-491.
  • Drane H M, Patterson D S, Roberts B A, Saba N (1980) Oestrogenic activity of soya-bean products. Food Cosmet Toxicol 18(4), 425-427.
  • Kilshaw P J, Sissons J W (1979) Gastrointestinal allergy to soyabean protein in preruminant calves. Allergenic constituents of soyabean products. Res Vet Sci 27(3), 66-71.
  • Sissons JW, Smith RH, Hewitt D (1979) The effect of giving feeds containing soya-bean meal treated or extracted with ethanol on digestive processes in the preruminant calf. Br J Nutr 42(3), 477-85.
  • Roy J H, Stobo I J, Shotton S M, Ganderton P, Gillies C M (1977) The nutritive value of non-milk proteins for the preruminant calf. The effect of replacement of milk protein by soy-bean flour or fish-protein concentrate. Br J Nutr 38(2), 167-87.
  • Kakade M L, Thompson R D, Engelstad W E, Behrens G C, Yoder R D, Crane F M (1976) Failure of soybean trypsin inhibitor to exert deleterious effects in calves. J Dairy Sci 59(8), 1484-1489.
  • Sissons J W, Smith R H (1976) The effect of different diets including those containing soya-bean products, on digesta movement and water and nitrogen absorption in the small intestine of the pre-ruminant calf. Br J Nutr 36(3), 421-38.
  • Rackis J J (1974) Biological and physiological factors in soybeans. J Am Oil Chem Soc 51(1), 161A-174A.
  • Kakade M L, Simons N R, Liener I E, Lambert J W (1972) Biochemical and nutritional assessment of different varieties of soybeans. J Agric Food Chem 20(1), 87-90.
  • Nitsan Z, Volcani R, Gordin S, Hasdai A (1971) Growth and nutrient utilization by calves fed milk replacers containing milk or soybean protein-concentrate heated to various degrees. J Dairy Sci 54, 1294-1299.
  • Melmed R N, Bouchier I A (1969) A further physiological role for naturally occurring trypsin inhibitors: the evidence for a trophic stimulant of the pancreatic acinar cell. Gut 10(12), 973-979.
  • Carter M W, Smart W W Jr, Matrone G (1953) Estimation of estrogenic activity of genistein obtained from soybean meal. Proc Soc Exp Biol Med 84(2), 506-508.

Other sources of information

  • Ishler VA, Varga GA (2017) Soybeans and soybean byproducts for dairy cattle. PenState Extension. Available at https://extension.psu.edu/soybeans-and-soybean-byproducts-for-dairy-cattle
  • Dei H K (2011) Soybeans as a feed ingredient for livestock and poultry. In:  Recent Trends for Enhancing the Diversity and Quality of Soybean Products. Krezhova, D (ed). New York, NY: InTech, pp 215-226.
  • Fluharty F L (2009) Protein and energy supplementation of crop residues for breeding cattle. Ohio Beef Cattle Letter, OSU Extension services, Ohio. Available at: http://beef.osu.edu/library/AltFeedSuplong.pdf

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