Effects of Feed Particle Size and Feed Form on Growth Performance, Nutrient Metabolizability and Intestinal Morphology in Broiler Chickens

This study was conducted to investigate the effect of feed particle size and feed form on growth performance, nutrient metabolizability and intestinal morphology in broiler chickens. This experiment was a 2×2 factorial arrangement including two feed particle sizes (fine and coarse) and two feed forms (mash and pellet). A total of two hundred and eighty eight day-old male Arbor Acre broilers were used in this six week experiment. Birds were randomly allotted to four dietary treatments with six replicates per treatment and twelve birds per replicate. The results showed that pelleting diets resulted in greater ADG (p<0.01), greater ADFI (p<0.01) and lower feed to gain ratio (F/G) (p<0.05) during starter, grower and overall period. Also, pelleting improved both apparent metabolizable energy (AME) (p<0.01) and the apparent metabolizability of crude protein (p<0.05) and organic matter (p<0.05) regardless of the phase. Reduction of feed particle size enhanced AME (p<0.05) during d 19 to 21. Increased villus height (p<0.05) and crypt depth ratio (p< 0.05) within duodenum, jejunum, and ileum were observed in birds fed the pellet diet compared with those given the mash diet. In conclusion, results indicated that feed pellets might enhance performance by improving nutrient metabolizability and digestive tract development. (