A total of 1,200 gilts was used to evaluate
the effects of replacing conventionally
processed soybean meal with extruded-expelled
soybean meal on finishing pig growth performance. Dietary treatments were arranged
in a 2 × 3 factorial with two sources of soybean meal (solvent-extracted or extruded-expelled) and three levels of added fat (none, 3.4, and 7% in Phase 1 than decreasing
in subsequent phases). Energy levels were adjusted such that the higher energy in extruded-expelled soybean meal (with or without added fat) was equal to that provided by solvent-extracted soybean meal
with added fat. From 54 to 135 lb, pigs fed
extruded-expelled soybean meal had improved
ADG and F/G compared to those fed solvent-extracted soybean meal. Increasing added fat in either extruded-expelled- or solvent-extracted soybean meal-based diets linearly improved ADG and F/G. From 135 to 270 lb, pigs fed extruded-expelled soybean meal and(or) increasing added fat had decreased feed intake. For the overall growing-finishing period, ADG was unaffected by increasing energy density. However, ADFI was decreased and F/G improved as energy density of the diet was increased either with extruded-expelled soybean meal and(or) added fat. Carcass leanness was not affected by dietary treatment. These results indicate that increasing the energy density of the diet by using extruded-expelled soybean meal and(or) added fat improves feed efficiency in finishing pigs reared in a commercial environment.
