1. Randox Food Diagnostics Ltd., 55 Diamond Road, Crumlin, BT29 4QY, United Kingdom.
2. Colorado Department of Agriculture, Division of Laboratory Services – Biochemistry Laboratory, 300 South Technology Court, Broomfield, CO 80021, USA.
3. University of Kentucky, Division of Regulatory Services, 103 Regulatory Services Bldg, Lexington, KY 40546, USA.
4. American Association of Feed Control Officials (AAFCO), Proficiency Testing Program, 1800 S. Oak Street, Suite 100, Champaign, IL 61820, USA.
5. Missouri Department of Agriculture, Bureau of Feed and Seed, 115 Constitution Drive, Jefferson City, MI 65109, USA.