PSV-21 effects of soybean meal and net energy level on nursery pig performance

Nursery pigs (n = 3,796; 17.6 kg BW) were used in a 22-d study evaluating the effects of increasing soybean meal on nursery pig performance. At 8 weeks of age, pens were allotted to treatment based on location in a randomized complete block design with 39 to 40 pigs per pen. Ten pens were placed on the positive control treatment and 12 pens placed on all other treatments. Experimental diets were fed in one phase (d 0 to 22) in meal form. Treatments included a positive control diet with 40% soybean meal and 1.8% choice white grease. Six diets were formulated with increasing soybean meal (17.5 to 40%) without added fat. Pigs were weighed on d 0, 13, and 22 to determine ADG, ADFI, G:F and NE efficiency. Growth data were analyzed as a randomized complete block design with pen as the experimental unit. Growth data were evaluated using linear and quadratic effects of soybean meal level and a pairwise comparison of the 40% soybean meal treatments with and without added fat. An outbreak of E. coli-associated disease was noted in the first 2 weeks of the experiment. Overall, increasing soybean meal tended to decrease (linear; P = 0.070) ADG, decreased (linear; P = 0.0001) ADFI, improved (linear; P = 0.0001) G:F and caloric efficiency, and reduced (linear; P = 0.050) removal rate (Table 1). Pigs fed the positive control had decreased (P = 0.019) ADFI and improved (P = 0.001) G:F compared to pigs fed the 40% soybean meal diet without added fat. These results suggest the net energy value for soybean meal was underestimated in diet formulation. Increasing soybean meal level in the diet reduced removal rate, suggesting soybean meal may provide added health benefits beside amino acids and energy.