Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Agricultural and Resource Economics

Committee Chair

Joseph S Moritz

Committee Co-Chair

Marie Krause

Committee Member

Janet Tou


The objectives of the first study were to assess performance and digestible amino acid concentration of diets fed to broilers that differed in diet formulation and degree of thermal processing. Basal diets were corn, soybean meal, and DDGS based and formulations were balanced to be similar in calculated energy and digestible amino acids. Treatments were arranged in a 3 x 3 factorial that varied in diet formulation (Basal, Basal + Meat and Bone Meal (MBM), and Basal + Bakery Byproduct (BBP)) and degree of thermal processing (Unprocessed Mash, Pellet, Double Pellet). Pelleted treatments were steam conditioned and extruded through a pellet die. Double Pellet treatments repeated this process. All treatments were ground to similar particle size and fed to ten replicate raised wire cages of 10 straight-run Hubbard x Cobb 500 broiler chicks for 18 d. Broilers provided a Basal + MBM diet improved FCR (P=0.0046). Pelleting and Double Pelleting improved FCR compared to Unprocessed Mash (P=0.0003). Formulation and processing effects interacted to affect LWG, digestible lysine, methionine, threonine, and cysteine concentrations (P< 0.05). Improvements to LWG were apparent only when Basal + MBM diets were thermally processed. Digestible amino acid concentration improved when Basal and Basal + MBM diets were thermally processed. However, digestible lysine and cysteine concentrations decreased when Basal + BBP were thermally processed. In vitro reactive lysine results did not support digestible lysine concentration results. Nutritional benefit or detriment of thermal processes associated with pelleting were dependent on diet formulation.;The objectives of the second study were to assess various commercial inorganic feed phosphates in diets that contained high fat distillers dried grains with solubles (DDGS) effect on feed manufacture variables. Diets with moderately high levels of corn DDGS are notoriously difficult to pellet due to their high fat and fiber content. Therefore the addition of inorganic phosphate feed ingredients, especially tricalcium phosphate has been anecdotally thought to improve feed manufacture and pellet quality of diets high in corn DDGS. Feed was manufactured on three separate days, each day denoting a replication of the experiment. Six experimental diets consisted of corn- and soybean meal-based diets without meat and bone meal were formulated to include either: 1) FP&S Dicalcium Phosphorus (DCaP), 2) Nexfos, 3) Bolifor, 4)Defourinated Phosphorous, 5) Mixture (1/5 Bolifor, 1/5 MSP, 3/5 DCP), or 6) Bolifor + SiO2. The inclusion of Deflourinate Phosphorous demonstrated decreased hot pellet temperature, motor amperage and pellet quality while increasing production rate relative to the diet that included Bolifor + SiO2 (P<0.05). It is thought that the improvements demonstrated for this product could be due to the physical aspects of the product. The inorganic feed phosphate ingredient that exhibited the densest and smallest particle size is Deflourinated Phosphorous. The small-diameter and high-density particles of Deflourinated Phosphorous could of provided greater inertia within the die, thus enhancing die scouring. The use of Bolifor demonstrated a significantly increased hot pellet temperature, but maintained similar motor amperage and production rate relative to diets that included DCP or Nexfos. Majority of pellet quality variables showed that diets containing Bolifor or DCP were similar yet superior to the diet containing the inorganic feed phosphate ingredient Nexfos.