Impact of U.S. Sorghum Particle Size on Broiler Performance and Digestive Health
Project Summary:
Project: Impact of U.S. Sorghum Particle Size on Broiler Performance and Digestive Health
Project Sponsor: United Sorghum Checkoff Program
Project Overview:
This research investigated whether U.S. sorghum can effectively replace corn in broiler diets and identified the optimal grinding size geometric mean diameter (dgw) to maximize bird growth and organ development. The study addressed a historical gap in data regarding modern, tannin-free U.S. sorghum varieties and their physical processing requirements.
The research focused on the following objectives:
- Determine hammermill settings required to achieve specific sorghum particle sizes (400–1200 µm) and evaluate their effect on feed flowability
- Measure the influence of these particle sizes on Body Weight Gain (BWG), Feed Intake (FI), and Feed Conversion Ratio (FCR)
- Assess changes in relative gizzard weight (RGW) and gizzard pH as indicators of digestive efficiency
Key Findings:
- Broilers fed sorghum-based diets exhibited higher BWG and FI than those on corn-based diets, with no negative impact on FCR.
- Optimal growth and gizzard development occurred at the 1,000–1,200 µm range.
- Coarser particles stimulated the gizzard, increasing its muscular weight and lowered the digesta pH.
- Grinding sorghum to a coarser size (1000-1,200 µm) improved the Composite Flow Index (CFI), making the feed easier to handle in bins and silos compared to finely ground sorghum.
This project confirms that tannin-free U.S. sorghum can effectively replace corn in broiler diets without compromising growth performance. To maximize the nutritional and economic value of U.S. sorghum, feed manufacturers should target a coarse grind of 1,000–1,200 µm. The suggested particle size contributes to a more active gizzard, leading to better bird health and potentially lower processing costs at the feed mill.
