Particle size and feed form in broiler diets: impact on gastrointestinal tract development and gut health

Abstract

The importance of feed particle size, as a tool to optimise the utilisation of feed and improve production efficiency in broilers, has attracted increased attention in recent years. Particle size reduction is widely believed to enhance the access of digestive enzymes to substrates because of the increased surface area of feed particles. Fine particles can negatively affect the development of fore-gut (proventriculus and gizzard), which plays an important role in intestinal health and nutrient utilisation. A well-developed fore-gut can be achieved by feeding coarse particles which is associated with improvements in gut motility and health. However, the results of studies considering the effect of feed particle size on upper gastrointestinal tract development have been inconclusive, because of the confounding effects of feed form (mash vs. pellets). Feed particle size influences the development of gastrointestinal tract and bird performance to a greater extent when the broilers are fed mash than pelleted diets. Particle size-reducing properties of the pelleting process may result in suboptimal gizzard development and changes in the intestinal morphology and microbiota profile.

The interactive influence of barley particle size and enzyme supplementation on growth performance, nutrient utilization, and intestinal morphometry of broiler starters

“…However, the pelleting process may further reduce the size of feed particles, especially of coarser particles, and equalize the differences in particle size distribution ( Svihus et al., 2004 ; Amerah et al., 2007b ; Abdollahi et al., 2013 ), suggesting that the particle size impact is more pronounced in mash diets than in pelleted or crumbled diets ( Zaefarian et al., 2016 ). However, some reports indicate that the effects of feed particle size on bird performance exist even after pelleting ( Nir et al., 1995 ; Naderinejad et al., 2016 ).…”

Wheat particle size, insoluble fibre sources and whole wheat feeding influence gizzard musculature and nutrient utilisation to different extents in broiler chickens

“…The presence of these materials in the diet imparts some benefits to the birds’ digestive system. The impact of diet texture on intestinal health and physiological functions has been well‐demonstrated in poultry (Svihus, ; Zaefarian, Abdollahi, & Ravindran, ). In modern poultry production, broiler diets suffer from a lack of structure, and this issue has ignited interest on the use of a so‐called structural component in commercial poultry diets (Svihus, ).…”

Upregulation of genes encoding digestive enzymes and nutrient transporters in the digestive system of broiler chickens by dietary supplementation of fiber and inclusion of coarse particle size corn

“…Strategies to improve broiler digestive efficiency and performance without reliance on antibiotics have been the focus for improving gut health and manipulating development of the gastrointestinal tract (GIT). A range of nutritional interventions including; increasing grain particle size, using whole grain, and including different sources or levels of dietary fiber and other feed additives, such as probiotics, bacteriophages, enzymes and phytobiotics are currently under investigation [ 2 – 4 ].…”