Replacement value of cottonseed meal for soybean meal in broilerchicken diets with or without microbial enzymes

摘要

A 4×2 factorial feeding trial was designed to investigate the effect ofreplacing soybean meal (SBM) with cottonseed meal (CSM) inwheat/sorghum/SBM-based diets fed with or without microbial enzymes in diets onthe performance, visceral organ development and digestibility of nutrients ofbroiler chickens. Four graded levels of CSM - none (0%), low (4%, 8%, and 12%),medium (5%, 10%, and 15%), and high (6%, 12%, and 18%) of complete diets instarter, grower and finisher, respectively were fed with or without 100 mg/kg ofxylanase and β-glucanase blend. Eight isocaloric and isonitrogenous dietswere formulated using least-cost method to meet the nutrient specifications ofRoss 308 male broilers. Each treatment was randomly assigned to 6 replicates (10birds per replicate). There were CSM-enzyme interactions ( < 0.05) on feed intake (FI) and weight gain (WG) in the starter phase. Enzymesupplementation improved ( < 0.05) feed conversion ratio(FCR) in the grower and finisher phases, and increased WG in growing andfinishing birds. CSM inclusion reduced ( < 0.05) the weightof gizzard and proventriculus in starter chicks, while these organs were bigger( < 0.05) in the grower phase. The test ingredientdecreased ( < 0.05) small intestinal weight in starter andgrower birds. The CSM increased the absolute weight of thighs( < 0.05) while breast meat was increased( < 0.01) by enzyme addition. Starch digestibility wasimproved ( < 0.01) by enzyme inclusion and decreased( < 0.01) by CSM. Enzyme supplementation improved( < 0.05) the ileal digestibility of gross energy andprotein. The results demonstrate that CSM can substitute up to 90% SBM inbroiler chicken diets without compromising performance, and the nutritive valueof CSM-containing diets can effectively be improved by enzymesupplementation.