Date of Graduation

2016

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Animal and Nutritional Sciences

Committee Chair

Joseph S Moritz

Committee Co-Chair

Robert L Taylor

Committee Member

Janet C Tou

Abstract

Experiments were conducted to evaluate various ingredients' effects on broiler, turkey, and porcine performance, as well as feed mill efficacy. In chapter 2, the effects of zinc (Zn) supplement source and corn particle size on broiler performance, breast yield, and tibia ash were assessed from d 1-40. Zinc treatments included a basal diet (no added Zn), 80 mg/kg Zn sulfate, and three diets with 40 mg/kg Zn sulfate + 40 mg/kg of varying Zn amino acid chelates, and corn particle size was either 550 mum or 1,050 mum. Broilers fed diets containing 550 ?m corn had higher feed intake (FI) and live weight gain (LWG) from d 1-22, while feed conversion ratio (FCR) was improved for broilers fed diets with 1,050 ?m corn from d 23-40 and d 1-40. Diets supplemented with 80 mg/kg Zn improved broiler performance compared to the diet without supplemental Zn, but no differences were observed between Zn sources for performance or tibia ash. In chapter 3, a study was conducted to determine mix uniformity, thermal stability, and pellet quality of diets supplemented with two particle sizes (2 or 3 mm) of transgenic phytase corn (TPC) and two concentrations (5,100 or 15,300 FTU/kg -- AOAC 2000.12) of granulated phytase. Mix uniformity was determined by calculating mixer coefficient of variation (CV) using chloride ion concentration and phytase activity of ten mash samples taken from various locations within the mixer. Each phytase diet was steam conditioned and pelleted at 80, 85, and 90°C and activity was measured to determine enzyme recovery. The results indicated that mix uniformity was better for granulated phytases than TPC, and mix uniformity was improved for 2 mm TPC compared to 3 mm TPC. The 2 mm TPC had the highest recovery at 80°C, while granulated phytases were superior to TPC products at 90°C. In chapter 4, three studies were conducted to determine porcine palatability of corn-soybean based diets supplemented with oil-extracted microalgae and subsequent performance. In study 1, Duroc x Yorkshire-Landrace crossbred pigs were fed diets containing either 0, 1, 2, or 4 % oil-extracted microalgae for a 14 d grow-out period. Average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) were similar among all treatments and pellet durability was numerically higher for the 4 % microalgae diet. In studies 2 and 3, pigs were fed diets containing either 0 or 4 % microalgae. All performance metrics (ADG, ADFI, and G:F) were similar among all treatments suggesting that oil-extracted microalgae can be used as a feed ingredient for swine. In chapter 5, the performance and carcass characteristics of two commercial turkey hen strains (Nicholas and Hybrid) and a test product turkey hen strain were evaluated from d 1-125. Secondary objectives of the study were to determine the effect of an elevated nutrient diet for feathering in the test product strain, and to determine genetic differences in lysine alpha-ketoglutarate reductase (LKR) activity at d 125. Hybrid hens had the largest LWG from wk 1-4, while Nicholas hens had larger LWG from wk 13-16. At d 125, performance, hot breast yield, and fat pad yield were similar among all three hen strains. The LKR activity was not different among strains, likely due to lack of performance differences among treatments.

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