Improvement of the nutritional value of high-protein sunflower meal for broiler chickens using multi-enzyme mixtures
Two experiments were conducted to determine the effect of replacing soybean meal (SBM) with a high-protein sunflower meal (HiSFM) without or with multi-enzyme mixtures on growth performance, nutrient utilization, jejunal digesta viscosity, and excreta moisture in broiler chickens. In experiment 1, 400 chicks were divided into 40 replicates of 10 birds and fed for 35 d a corn-soybean meal (CSBM) control diet or CSBM with 25 (HiSFM25), 50 (HiSFM50), 75 (HiSFM75), or 100% (HiSFM100) of total SBM replaced by HiSFM. During d 0 to 35, increasing HiSFM content in diets linearly reduced (P < 0.0001) BW, FI, and BW gain (BWG). Feeding HiSFM25 or HiSFM50 resulted in similar growth performance as CSBM (P > 0.05). In experiment 2, 120 chicks were divided into 24 replicates of 5 birds and fed CSBM or HiSFM75 diet without or with enzyme A (supplying 4,000, 500, and 8,000 U/kg of xylanase, alpha-amylase, and protease, respectively) or enzyme B (supplying 1,700, 1,100, 240, 30, 1,200, 360, 1,500, and 120 U/kg of cellulase, pectinase, mannanase, galactanase, xylanase, glucanase, amylase, and protease, respectively) for 21 days. Excreta moisture content was determined weekly, and birds were euthanized on d 22 to collect jejunal and ileal digesta for viscosity and apparent ileal digestibility (AID) measurements, respectively. Compared with CSBM, feeding HiSFM75 reduced (P < 0.05) BWG and G: F, enzymes A and D alleviated BWG and G: F reduction (P < 0.05), and enzyme A reduced (P = 0.037) the excreta moisture content, whereas the treatments did not influence AID or jejunal digesta viscosity measurements. In conclusion, experiment 1 results show that HiSFM can replace up to 50% of SBM without depressing growth performance in either the starter or finisher phase, whereas experiment 2 shows that enzymes A and B supplementation can alleviate the growth depression associated with feeding HiSFM75. These results suggest that enzyme supplementation can enhance HiSFM inclusion in broiler diets without affecting productivity or barn hygiene management.