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ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Research Project #443129

Research Project: Effect of Particle Size and Feed Quality on Performance and Intestinal Function in Broiler Chickens with Sub-clinical Enteric Infections

Location: Poultry Research

Project Number: 6064-32630-011-001-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 4, 2022
End Date: Aug 3, 2027

Objective 1: Conduct research to determine effects of corn particle size and feed quality in broiler starter diets on performance, yield, and gastrointestinal function.

A survey will be conducted from two to three broiler integrators to determine the average corn particle size utilized in their feeds and will be used to determine the range of corn particle sizes tested. Three corn particle sizes will be tested in each phase and will consist of “low,” “medium,” and “high.” Three feed qualities will be tested and will consist of “low,” “medium,” and “high” and derived from previous research. Fines will be added to an original pelleted diet and hand-mixed in differing proportions to create low (40% intact pellets: 60% feed “fines”), medium (60% intact pellets: 40% feed “fines”), and high (80% intact pellets: 20% feed “fines”). Corn will be ground in bulk via hammer mill to the predetermined “low,” “medium,” and “high” particle sizes; these particle sizes will be stored separately and added into the diet later. Next, a common basal diet will be batched (less the entire corn inclusion); these batches will be equally allocated to one of each corn particle size treatment. Additionally, an equal proportion of this basal diet (less corn) will be saved and used later in treatment creation. Each previously described aliquot will be combined with its pre-assigned corn particle size and subsequently pelleted using commercial mimicking feed manufacture practices. Resulting feed quality will be assessed by determining percent fines. Next, the proportion of basal diet saved previously (less corn inclusion) will be pelleted and subsequently ground to resemble feed “fines.” This deficient feed “fines” diet will be divided and separately mixed with the appropriate proportion of corn from each corn particle size treatment. These diets will then be proportionally added to the originally manufactured complete feed (unmodified pellets) varying in corn particle size to then create varying pellet/feed qualities. These steps are necessary to expose the majority of the feed to feed manufacture conditions (high heat, moisture, pressure); however, control corn particle sizes and feed qualities. For Study 1 (starter phase), all feed will be batched and pelleted without the corn inclusion, then crumbled. Gap width of the crumbler will then be manipulated to create the three crumble qualities; each crumble quality will be equally allocated to a corn particle size treatment and hand-mixed with the appropriate proportion of corn to create one of 9 complete feed treatments. This study will be conducted in a floor pen facility equipped to mimic commercial type environment. Diets will be analyzed for proximate analysis and amino acid content. Gastrointestinal sampling will include organ weights (gizzard, proventriculus, jejunum, ileum, and ceca) and lengths of the jejunum, duodenum, and ileum; pH of the gizzard will also be recorded. Performance metrics (feed intake, body weight, feed conversion ratio) will be assessed.