TITLE:
UTILIZATION OF FULL-FAT SOYA OR SOYABEAN MEAL BASED DIETS SUPPLEMENTED WITH VARYING LEVELS OF PROTEASE ENZYME IN TURKEY DIETS
NAME: OKORODUDU Avwerosuoghene
MATRIC NO: PG 11/0143
YEAR OF ADMISSION: 2014/2015 session
CENTRE: World Bank Centre of Excellence in Agricultural Development and Sustainable Environment
PROGRAMME: Livestock Science and Sustainable Environment
DEGREEAWARDED: Ph.D AgSE (Monogastric Animal Nutrition)
DEFENSE DATE: 18/09/2018
ABSTRACT
Enzyme-mediated improvement of feed digestibility has a direct effect on the quantity of feedstuffs needed to satisfy the nutritional requirements of poultry by improving performance through increased nutrient utilization and reduction of nitrogen and phosphorus content in the droppings. This increases sustainable poultry production and minimizes the negative impacts on the environment. Two experiments were conducted to evaluate the utilization of dietary soyabean meal (SBM) or full-fat soya meal (FFSB) supplemented with a commercial protease enzyme at varying levels on the performance, nutrient digestibility, blood metabolites, carcass yield and feed cost of rearing turkeys. Experiment 1: One hundred and eighty 56-day old, British United Turkeys (BUT) were allotted on weight equalization basis into 6 treatment groups in a 2×3 factorial arrangement of 2 soya bean sources (SBM, FFSB) and 3 levels of protease supplementation (250ppm, 500ppm, 750ppm). Experiment 2: One hundred and eighty 28-day old BUTs were randomly allocated on weight equalization basis to 6 treatment groups of 3 sources of dietary soya (SBM, SBM/FFSB (50:50), or FFSB) with or without protease supplementation (0ppm, 500ppm) in a 3×2 factorial arrangement. Data obtained were analyzed using Analysis of Variance in a Completely Randomized Design. In experiment 1, growing turkeys fed FFSB+250ppm protease had the best FCR, least (P<0.05) feed cost and feed-cost/weight gain. Finishing turkeys fed SBM+500ppm protease had the best FCR and least feed-cost/weight gain. At the growing phase, eosinophil count was highest (P<0.05) and monocyte count lowest in those fed SBM+250ppm, while PCV and WBC were higher (P<0.05) in finishing turkeys fed SBM. At 12 weeks, turkeys fed FFSB+250ppm protease had the lowest albumin and highest uric acid contents. Cholesterol and HDL shared higher values in finishing turkeys fed FFSB, protease supplementation showed no significant effect. Nutrient utilization improved (P<0.05) with increasing levels of protease enzyme. Wings, drumstick and breast cut-up parts were heavier (P<0.05) in turkeys fed FFSB based diets than SBM based diets. In experiment 2, weight gain, feed intake, and feed-cost/weight gain were higher (P<0.05) in starting turkeys fed SBM based diets, they also had the best FCR and least feed cost/kg diet; protease supplementation increased the feed intake, feed cost/kg diet, and the feed-cost/kg weigh gain. Growing turkeys fed SBM based diets had a better FCR, reduced (P<0.05) feed cost/kg diet and feed-cost/weight gain. Finishing turkeys fed SBM without protease had the poorest performance. Growing turkeys fed SBM based diets had higher (P<0.05) WBC, while protease enzyme supplementation reduced the WBC count and increased the neutrophil count. Serum metabolites, nutrient digestibility and energy metabolisability of starting and growing turkeys were also significantly influenced by both dietary soya and level of protease supplementation. The study concluded that SBM based diets were better for growing turkeys while FFSB based diets were better for finishing turkeys as it reduced the feed cost/kg diet, increased the weight gain, improved the carcass yield and blood metabolites. In addition, protease supplementation at 500 ppm reduced the feed cost/weight and improved the wellbeing of turkeys as indicated from the blood profile.
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