Commercially Processed Glandless Cottonseed Meal for Starter, Grower and Finisher Swine

Growth trials with weaned pigs (28 d old and 7.5 kg initially) and growing-finishing pigs (19 to 97 kg), plus a digestion trial were conducted to evaluate the nutritional value of commercially processed glandless cottonseed meal (GCSM). The GCSM contained 43% protein, 15.5% fiber, 1.62% lysine and .038% total gossypol. In the growth trials, GCSM was substituted in 20% increments for 0 to 100% of the supplemental protein in corn-soybean meal-based diets. Crystalline lysine was added to all GCSM diets to make them isolysine with the control corn-soybean meal diets. Increasing increments of GCSM resulted in linear reductions (P<.01, P<.05 or P<.10) in daily gain and linear increases (P<.01, P<.01 and P<.05) in feed/gain for pigs during the starter, grower and finisher trials, respectively. However, examination of the data indicated similar performance for pigs fed 0 to 40% supplemental GCSM protein, and only at the 60 to 100% levels was performance substantially reduced. Results from all growth trials indicated that GCSM plus lysine can be used to replace at least 40% of the supplemental protein in corn-soybean meal-based diets without affecting performance. Results of the digestion trial indicated similar or greater digestibilities of N and all essential amino acids for GCSM than soybean meal when measured at the end of the small intestine. The one exception was lower (P<.01) lysine digestibility (77.4 vs 84.0%) for GCSM. Estimated digestible lysine contents were similar for the soybean meal control diets and GCSM-containing diets of the growth trials, suggesting that some other factor was responsible for the lowered performance at the higher levels of GCSM.