Riska Sri Wahyuni Haris 1, Sri Purwanti 2,3 and Jasmal Ahmari Syamsu 2,4,5,*
1Master's Program in Animal Science and Technology, Faculty of Animal Science, Universitas Hasanuddin, Makassar, Indonesia; 2Faculty of Animal Science, Universitas Hasanuddin, Makassar, Indonesia; 3Poultry Nutrition and Feed Research Group, Universitas Hasanuddin, Makassar, Indonesia; 4Feed Technology and Industry Research Group, Universitas Hasanuddin, Makassar, Indonesia; 5Center of Research and Development for Livestock Resources and Tropical Animals, Universitas Hasanuddin, Makassar, Indonesia
*Corresponding author: jasmal.syamsu@unhas.ac.id
Corn particle size distribution is an important factor influencing the physical characteristics of feed and nutrient utilization in poultry diets. This study evaluated the effects of different corn particle size distributions on feed physical characteristics, nutrient composition, and in vitro nutrient digestibility, and identified the most suitable particle size distribution to balance feed physical characteristics and nutrient utilization in layer diets. The study was conducted in two sequential stages. Stage I characterized the particle size distribution of hammer-milled corn and evaluated its physical characteristics, including bulk density and angle of repose. Stage II evaluated seven dietary treatments containing different proportions of coarse and fine corn particles. Nutrient composition was analyzed using Near Infrared Reflectance Spectroscopy (NIRS), whereas in vitro protein and starch digestibility were determined by enzymatic digestion. Hammer-milled corn was dominated by coarse particles (86.43%), whereas fine particles accounted for only 13.57% of the total sample. Particle size exhibited a positive relationship with bulk density and a negative relationship with angle of repose, indicating that coarse particles possessed superior packing efficiency and flowability. Corn particle size distribution significantly affected protein and starch digestibility (P<0.05). The highest protein digestibility was observed in the diet containing 25% coarse particles and 75% fine particles (69.56%), whereas the highest starch digestibility was obtained in the diet containing 100% fine particles (76.86%). Among the treatments evaluated, the diet containing 25% coarse particles and 75% fine particles provided the most suitable overall response by combining the highest protein digestibility, high starch digestibility, and favorable feed physical characteristics. These findings suggest that balancing coarse and fine particle proportions, rather than maximizing either fraction individually, may represent an effective strategy for improving feed characteristics and nutrient utilization in layer diets.