Effect of anti-nutritional factors of oilseed co-products on feed intake of pigs and poultry

Abstract

Soybean, canola, camelina and flaxseed co-products from the oilseed industry are used to formulate pig and poultry feeds. However, these co-products contain various anti-nutritional factors (ANF). The major ANF in soybean and potentially co-products is trypsin inhibitor (TI). Pigs and poultry can tolerate TI levels up to 3.00 and 4.00 TIU/mg in the diet, respectively. Solvent-extracted soybean meal has low TI activity (<14.0 TIU/mg); most TI is destroyed during the desolventising-toasting stage of oil extraction. Thus, inclusion of soybean meal in diets for pigs and poultry does not affect feed intake and nutrient utilization. However, soybean or expeller-pressed soybean co-products can contain considerable amounts of TI (>50.0 TIU/mg), implying that the raw soybean or expeller-pressed soybean co-products should be sufficiently heated to inactivate most of the TI before feeding. The major ANF in canola co-products are glucosinolates. Poultry and pigs can tolerate up to 2.00 and 2.50 μmol/g of glucosinolates in their diets. Total glucosinolate content in most canola co-products is moderate (<10 μmol/g). Thus, while co-products from modern canola cultivars do not affect feed intake, dietary inclusion of original canola co-products (with total glucosinolate content of ≤35 μmol/g) reduced feed intake of grow-finish pigs by 80 g/day and of broiler chickens in the starter phase by 4 g/day. Glucosinolates and TI are the major ANF in camelina co-products. In camelina co-products, total glucosinolate content ranged from 34.4 to 36.3 μmol/g and TI activity from 12 to 28 TIU/mg. Camelina co-products are not solvent-extracted and thus have high TI activity. Dietary inclusion of camelina co-products reduced feed intake of broiler chickens in the starter phase by 3.4 g/day. Cyanogenic glucosides are the major ANF in flaxseed co-products. Flaxseed meal contained 127 mg cyanogenic glucoside/kg. Dietary inclusion of flaxseed meal reduced feed intake by poultry by 3.4 g/day. In conclusion, soybean, canola, camelina and flaxseed co-products contain various ANF that reduce feed intake by pigs and poultry.