EFFECT OF CORN PARTICLE SIZE MILLING ON BROILER, PULLET, AND LAYER GROWTH, PERFORMANCE, AND DIGESTIBILITY
Open Access
- Author:
- Kitto, Lisa Dorene
- Graduate Program:
- Animal Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- October 31, 2017
- Committee Members:
- Paul H Patterson, Thesis Advisor/Co-Advisor
R. Michael Hulet, Thesis Advisor/Co-Advisor
Alan L. Johnson, Committee Member
Gregory W. Roth, Committee Member - Keywords:
- poultry
corn particle
particle size
broiler
layer
pullet
digestibility
milling - Abstract:
- Corn particle size (PS) is a relatively unexplored topic regarding its impact on commercial poultry performance grown for meat or eggs. Additionally, there are potential feed fabrication aspects to consider as mills could potentially save machine energy, wear, and money by modifying PS. The objectives of the following studies were to: 1) assess hammer mill energy usage and economic efficiency grinding corn to different geometric mean diameters (GMD), 2) evaluate the nutrient digestibility, growth performance, and carcass characteristics of broiler chickens fed treatment GMD corn, and 3) evaluate the growth and performance of pullets and subsequent productivity and egg quality of laying hens fed corn GMD treatments. Cooperator feed mill Wenger Feeds, LLC (Rheems, PA) delivered two batches of corn ground to 600, 900, 1200, and 1500 µm by hammer mill. Energy and machine efficiency show larger PS (1200 and 1500 µm) lend themselves to greater efficiency, tonnes per hour (TPH) throughput, and lower cost/tonne than 600 and 900 µm. Four live bird studies followed: First, a broiler digestibility study was conducted where apparent ileal digestibility (AID) and true ileal digestibility (TID), which are ways to measure the ability of amino acids to be absorbed into the bloodstream through the gastrointestinal tract, and were measured to determine level of nutrient absorption through the small intestine of 35 day old male broilers. Second, a broiler floor pen study at commercial bird density was performed with crumbled and pelleted diets. Birds fed the 600 and 900 µm corn diets showed increased body weight (BW) and body weight gain (BWG) but no significant differences between treatments for feed intake (FI) or feed conversion ratio (FC). In a third study, commercial egg laying pullet chicks fed the 600 µm corn through to maturity had consistently heavier BW than those of other PS treatments. Lastly, from 19 – 43 weeks of age, hens in conventional cages were fed corn based treatment diets formulated in a phase fed program, with diets consisting of 50-60% ground treatment corn. Throughout the hen study there were no significant differences with the exception of yolk color, which was measured using a Roche yolk color fan and is tied to consumer preference. It was found the 600 µm treatment yolks were reduced compared to the 900, 1200, and 1500 µm treatments at 35, 43 weeks of age, and overall. Body weight (BW), FI, day at first egg, and the number of preovulatory follicles, those follicles in the rapid growth phase before selection, remained unchanged throughout the hen study, indicating corn particle size has little to no effect on hen BW, nutrient utilization for follicular recruitment, egg production, or quality of commercial hens.