In April 2025, the Iowa Pork Industry Center (IPIC) released a detailed fact sheet outlining the procedures and importance of conducting mixer uniformity tests in swine feed manufacturing. This test plays a critical role in ensuring consistent nutrient distribution in feed, which directly impacts animal health, performance, and regulatory compliance.
The fact sheet—IPIC 210—emphasizes standardized protocols for evaluating ingredient dispersion using horizontal, vertical, or continuous mixers. It outlines sampling schemes, trace substance selection (e.g., salt, minerals, or amino acids), and proper lab testing methods following AOAC standards. A coefficient of variation (CV) below 10% is considered excellent mixer performance, while values above 20% indicate poor uniformity.
Mark Storlie, ISU swine field specialist and author of the guide, also introduces the “Feed Uniformity Test Tracker,” a downloadable spreadsheet tool designed to simplify CV calculations and maintain a testing history.
Testing is recommended:
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Within 90 days of installing a new mixer
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After major repairs or modifications
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Every 1–3 years, depending on facility protocols
This publication provides a foundation for feed mill operators to improve quality control and meet regulatory expectations, particularly from agencies like the Canadian Food Inspection Agency (CFIA).
📄 View the full IPIC 210 fact sheet (PDF)
For more feed nutrition resources, visit: https://www.ipic.iastate.edu/nutrition.html
