The Nutritional Value and Safety of Genetically Unmodified Soybeans and Soybean Feed Products in the Nutrition of Farm Animals

Abstract

Post-extraction soybean (Glycine max (L.) Merr.) meal is widely used as a basic protein feed for farm animals, especially poultry and pigs. Products made from unmodified soybean seeds are an alternative to imported GMO soybean meal. The aim of the study was to develop feed products from popular European varieties of genetically unmodified soybeans, which can be produced on small and medium-sized farms, and to assess their nutritional value and safety to livestock. The research was conducted on the seeds of three soybean varieties and two types of feed products resulting from thermobaric treatment (extrudate) and oil pressing (soybean press cake). The mould and yeast contamination of domestic seeds was negligible. The thermobaric and pressing treatments lowered the content of fungi by 97%. The products were considered free from mycotoxins. In comparison with full-fat soybean seeds, the protein content in the products was up to 19% higher, and 92% of the total lysine remained available. The products had lower content of antinutritional ingredients (trypsin inhibitors) and the urease activity was reduced by 52–59% and 99%, respectively. The experiment showed that the European genetically unmodified soybean feed products were characterised by good quality, mycotoxicological purity and high nutritional value for farm animals.

Keywords

• genetically unmodified soybeans
• soybean seed extrusion
• soybean seed press cake
• mycotoxicology
• antinutritional factors
• available lysine