AOAC RI ERP E-Book - DS DF

OMA 2014.10 C: Collaborative Study Manuscript Expert Review Panel Use Only September, 2017

2013 Dietary Starch in Animal Feeds Collab Study Protocol 072513

RECOMMENDATION : Recommend Study Director: Mary Beth Hall Research Animal Scientist United States Department of Agriculture – Agricultural Research Service U. S. Dairy Forage Research Center

1925 Linden Drive Madison, WI 53706 United States MaryBeth.Hall@ARS.USDA.GOV

STUDY DESIGN PROPOSAL GUIDE: 1. Scope/applicability.

This method is suitable for determining dietary starch in animal feedstuffs. The target dietary starch concentrations evaluated in the study will be 1% to 63% of sample on an air dry basis. This method replaces AOAC Method 14.075 . 2. Materials/matrices. The study set consists of feed samples from multiple matrices. The dry materials are ground to pass a 40 mesh screen, wet samples homogenized, and a high fat sample was processed in a cutting mill equipped with a cooling water jacket (Knifetec 1095 Sample Mill, Foss North America, Eden Prairie, MN). Samples for analysis are alfalfa pellets, wet pet food, dry pet food, commercial low starch equine feed, corn grain, dried corn silage, soybean meal, dried distillers grains, commercial lactating dairy cattle feed, and commercial swine or poultry feed. Samples will contain 1 to 63% as dietary starch that is naturally occurring in the samples. Participants will be provided with pre-trial samples and proficiency with the method must be demonstrated prior to the distribution of the study materials. The pre-trial specimens will include glucose standard solutions in 0.2% benzoic acid, glucose and corn starch control samples, and 3 ground samples with which to familiarize themselves with the handling characteristics of feed samples. The study materials were prepared and divided into individual portions of a minimum of 20 grams. The materials are randomly numbered with each laboratory being provided with duplicate (blind) portions from each material. Each laboratory will receive 20 study materials (10 materials as blind duplicates) as well as a number of QA materials including glucose and corn starch to be used as control samples. 3. Test sample preparation and handling. The samples will be provided in ground or homogenized form. Laboratories will have to subsample from the portion sent to them. No other preparation of the samples will be required. Samples will be stored frozen by the labs (-20°C) until thawed for analysis. 4. Quality assurance. AOAC Research Institute ERP Use Only

25 of 32