Extruded full-fat soybean as a substitute for soybean meal and oil in diets for lactating sows: the effect on litter performance and milk composition

The aim of this study was to determine the effect of supplementing different concentrations of extruded full-fat soybean (EFS) to corn-soybean meal-based lactation diets, at the expense of soybean meal and oil, on sow and litter performance. During gestation, a total of 60 Landrace x Yorkshire multiparous sows were fed the same gestational diet. After farrowing, sows were randomly allotted to one of four treatments including Control (corn-soybean meal-soybean oil), and 6.1%, 12.2%, and 18.3% EFS diets, until Day 21 of lactation. Individual weight at weaning tended to be heavier in the 12.2% EFS group as compared with Controls (P = 0.07). Litter weight in 12.2% EFS group was significantly increased compared with Controls, representing an increase of 7.8%. Average daily feed intake of sows in the 12.2% EFS group tended to increase (P = 0.08) when compared with the other three groups. At Day 21 of lactation, fat and protein content in the milk of the 12.2% EFS group were higher than those of the Control group (P < 0.05). In conclusion, these results demonstrated that feeding lactating sows diets supplemented with EFS had a positive effect on milk composition as well as litter performance. Among the three dietary levels of EFS tested, 12.2% EFS supplementation level showed preferable reproductive performance.