Replacement of Soybean Meal by Cottonseed Meal and Peanut Meal or Both in Low Energy Diets for Broilers

In a feeding trial, 936 1-day-old male (Hybro) broilers were allocated equally to 72 cages to evaluate cottonseed meal (CSM) and peanut meal (PNM) as substitutes for soybean meal (SBM). The 12 treatments were completely randomized among the cages. All diets were balanced to maintain equal levels of sulfur amino acids and lysine and were kept isocaloric (2,850 kcal ME/kg) and isonitrogenous (CP 21%). Feeding diets containing increasing amounts of CSM (0, 8, 16, and 24%) had a negative linear effect (P less than .05) on body weight gain and a positive linear effect (P less than .05) on feed:gain ratio of broilers to 3 wk of age. Diets with 8, 16, and 24% CSM contained 0, 196, and 310 ppm free gossypol, respectively, after chelation with iron from the feedstuffs and premix used in the diets. The improved growth and feed intake (P less than .05) resulting from the addition of 600 ppm Fe to the diet containing 24% CSM suggested that the negative effect of CSM was due to the high content of free gossypol. Increasing PNM from 5 to 10 and 15% had a negative linear effect (P less than .05) on body weight gain at 3 wk of age, due to the elevated levels of total iron in the 10 and 15% PNM diets (390 and 520 ppm, respectively). Addition of CSM at 8% with PNM at 5 or 10% had a negative linear effect (P less than .01) on body weight gain at 3 and 6 wk of age and a positive linear effect (P less than .05) at 3 wk of age on feed:gain, due to the high iron contents of 330 and 460 ppm, respectively.