Semester

Fall

Date of Graduation

2012

Document Type

Dissertation

Degree Type

PhD

College

Davis College of Agriculture, Natural Resources and Design

Department

Animal and Nutritional Sciences

Committee Chair

Joseph S. Moritz

Committee Co-Chair

Gary K. Bissonnette

Committee Member

Hillar Klandorf

Committee Member

Donald McIntyre

Committee Member

Janet C. L. Tou

Abstract

The majority of the research in this dissertation was conducted specifically to benefit a local turkey integrator, Virginia Poultry Grower's Cooperative, which has turkey growers in both West Virginia and Virginia. All of the research presented in this dissertation is applied in nature and may be directly implemented in the commercial poultry industry to improve production. Many commercial feed mills utilize low mixer-added fat (MAF) to increase ingredient binding opportunities and pellet quality, but this technique may decrease feed nutrient digestibility. In Chapter 2, two experiments were conducted in order to determine the best feed manufacture technique (MTECH) to maximize pellet quality and subsequent true amino acid digestibility (TAAD) of practical turkey diets. Experiment 1 was a 3 Binder (Binder 1, Binder 2, or No Binder) x 2 MTECH (1% MAF + 38.1 mm die or 3% MAF + 44.96 mm die) factorial design that utilized practical turkey starter diets manufactured at West Virginia University's pilot feed mill. In Experiment 2, diets containing either No Binder of Binder 1 at each MTECH were chosen to test TAAD, using cecectomized roosters. Results from this research established that Binder 1 and 3% MAF maintained feed quality while improving amino acid digestibility using a rooster model. This led to the development of the experiments conducted in Chapter 3, where the objective was to determine the effect of commercial turkey starter diets varying in amino acid density (AAD) (Normal or High) and MTECH (MTECH1-1% MAF + 0.5% Sand or MTECH2-3% MAF + 0.5% Binder) on commercial feed mill manufacture efficiency, D10-40 poult performance and broiler feed retention time. Feed quality was maintained utilizing MTECH2 as compared to feed produced with MTECH1. In addition, MTECH2 also created larger, more uniform crumbles. Chapter 3 results indicated that High AAD diets manufactured with MTECH2 may enhance poult performance due to improved feed quality and associated benefits, increased feed retention time in the gastrointestinal tract, and perhaps improved fat digestibility. Chapter 4 was designed in order to test diet formulation strategies (one of two Yeast Product (YP) inclusion) to improve brooder phase performance (D1-42). Another goal of research conducted in this chapter was to determine feed form advantages during grower/finisher phase production of large toms (D42-118) due to this period of high feed volume consumption. On D42 one of the tested YP improved poult ending weight and feed conversion ratio (FCR). At the end of grow-out, feeding high quality pellets produced toms that were 0.29 kg/bird heavier with 9 points lower FCR, as compared to toms fed ground pellets. Research in Chapter 5 was conducted with the overall goal of improving brooder phase performance (D1-42) by varying phytase level inclusions (Normal or High) into commercial turkey diets. Recent research has indicated that phytase inclusion may help decrease gut inflammation and subsequent immune response caused by phytate phosphorus (P); therefore, other objectives of research conducted in Chapter 5 were to assess the effect of increasing phytase inclusion on D40 gut inflammation via ileal mRNA expression of Interleukin (IL)-1beta and IL-6, and D40 total P content of litter. Phytase inclusion levels had no effect on brooder phase poult performance or gut health; however, High Phytase diets fed to poults placed on fresh shavings from D1-40 reduced total P content of litter by ∼11%. For the last chapter of this dissertation (Chapter 6) two experiments were conducted that utilized practical diets and regression analyses to evaluate the utilization of lysine (Experiment 1) and phosphorus (Experiment 2) in corn distiller's dried grains and solubles (DDGS) using a broiler chicken model. This research is warranted because technologies employed to produce this coproduct of corn ethanol production have evolved; thereby potentially changing the availability of its key nutrients. In both Experiments 1 and 2, multiple analyses verified the original nutrient coefficients for digestible lysine (0.7031%) and available P (0.66%) suggested for the specific DDGS tested; however, depending on analysis and performance variable, availability may be underestimated by up to 0.07 and 0.02 percentage points, respectively.

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