A Review on Feed Particle Size and Form: Implications on the Performance and Gut Health of Poultry

Feed ingredients, particle size, and texture are well-acknowledged factors affecting nutrient digestibility, feed utilization, gut health development, and overall production performance of poultry birds. Therefore, it has been a topic of interest for nutritionists and feed producers to optimize poultry production efficiency. Grinding, the second most expensive process during feed manufacturing, has been proposed to modify ingredient particle size. It is investigated that changes in the feed ingredients' particle size can significantly affect poultry birds' production, thus increasing particle size to the recommended level for improving poultry performance and saving costs from over-grinding. Providing feed in pelleted form is an advanced form of feeding with many benefits compared to mash, such as improved nutrient digestibility, feed palatability, and reduced ingredient segregation. The modern poultry industry has traditionally fed birds with pelleted diets.Moreover, pellet quality and conditioning temperature significantly impact bird production performance. The feed form and feed ingredient particle size also significantly influence digestive system development and intestinal microflora, affecting birds' overall performance. This review paper will discuss the published literature on feed form and particle size on bird performance, passage rate, gut development, feed intake, and nutrient digestibility.