Metabolism and Nutrition–nutrition I

Abstract

139 Effect of expanded cottonseed meal on laying performance , egg quality, concentrations of free gossypol in tissue, serum and egg of laying hens. Three hundred sixty Hy-Line brown hens at 40 wk of age were randomly allocated to 5 treatments, each of which included 4 replicates of 18 hens. After an expanded process of cottonseed meal (CSM), free gos-sypol (FG) content in CSM was decreased from 1.24 to 0.40 g/kg. The dietary treatments were corn-soybean meal based diets supplemented with 6% CSM and 6, 8, and 10% expanded cottonseed meal (ECSM). The experiment lasted 9 wk. Results were analyzed by general linear models using SPSS. Hens fed 8% ECSM had higher (P < 0.05) laying rate and average egg weight than those fed 6% CSM. ADFI increased as the levels of ECSM increased, and hens fed 10% ECSM had highest (P < 0.05) ADFI. Birds fed 6% CSM and 10% ECSM had lower (P < 0.05) albumen height and Haugh unit than those in other groups. Hens fed 6% CSM diets produced egg yolk with severe (P < 0.05) discoloration. kg in yolk, albumen, liver, kidney, and muscle of 10% ECSM group, respectively). Hens fed 6% CSM and 10% ECSM had the highest (P < 0.05) FG concentrations in the liver compared with those in the kidney and muscle, and higher (P < 0.05) FG residues in yolk than those in albumen. There was significant (P < 0.05) interaction between dietary levels of ECSM and different samples in concentrations of FG. In conclusion, FG in CSM can be reduced by 68% through an expanded process and ECSM can be available in laying hens at up to 10% of the total diet and an appropriate replacement of soybean meal with ECSM may improve performance in laying hens. 140 Effect of main cereal and mean particle size of the diet on the pattern of voluntary feed intake in brown egg laying hens. A. An experiment was conducted to study the effect of main cereal and mean particle size (MPS) of the diet on particle size preference of 48-wk-old hens. The experiment was completely randomized with 10 treatments organized as a 2 × 5 factorial with 2 main cereals (barley vs. corn) and 5 particle sizes that resulted from grinding the cereal with a hammer-mill provided with a 4-, 6-, 8-, 10-, or 12-mm screen. Each treatment was replicated 5 times and …