Particle size and feed form manipulation have emerged as alternatives to improve poultry performance. The objective of the study was to elucidate the effect of particle size and feed form on broiler performance and processing yield from 1 to 39 d of age. A total of 1800 d old male Cobb 500 birds were randomly assigned to 9 dietary treatments with 8 replicate pens per treatment and 25 birds per pen. The experiment consisted of a 3 × 3 factorial arrangement of 3 corn particle sizes (750, 1150 and 1550 μm) and 3 feed forms (mash, 3.0- and 4.0-mm pellets) provided from 1 to 39 d. Feed intake and BW were determined at 17, 27 and 39 d of age and FCR was calculated by using the weights of mortality. On d 40, 10 birds per pen were processed and on d 41, carcasses were deboned to determine meat yield. Data were statistically evaluated as a 3 × 3 (feed form × corn particle size) factorial arrangement in a randomized block design. Broilers fed 3.0- and 4.0-mm pellets had higher BW, FI and lower FCR (P<0.05) compared to broilers fed mash at 39 d of age. Broilers fed diets with 750 µm corn particle size had higher BW (P<0.05) than broilers fed diets with 1550 µm at 39 d of age, while broilers fed diets with 1150 µm had an intermediate BW. Broilers fed diets with 750 µm corn particle size had higher FI (P<0.05) than broilers fed diets with 1150 and 1550 µm at 39 d of age. Particle size of corn did not influence FCR at 39 d of age. Broilers fed 3.0 mm pellets had the heaviest (P<0.05) carcass and breast weights, followed by broilers fed 4.0 mm pellets and the lowest weights by broilers fed mash. Tenders and wings weight were similar among broilers fed 3.0- and 4.0-mm pellets, but higher (P<0.05) than broilers fed mash. Broilers fed diets with 750 µm corn particle size had heavier carcass and breast weight (P<0.05) than broilers fed diets with 1550 µm, with 1150 µm having an intermediate carcass and breast weight. Furthermore, broilers fed diets with 750 µm corn particle size had higher tender weight and yield (P<0.05) than broilers fed diets with 1150 and 1550 µm. These results showed that feed form and particle size influence broiler performance and processing yield of Cobb 500 broilers.ç
Key Words: Cobb, feed efficiency, feed form, particle size.
Abstract presented at the International Poultry Scientific Forum during IPPE 2020.