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Simple & Rapid Tests for the Quality of Animal Feeds


The focus of the proposed work is to determine the feasibility and utility of a dry chemistry point-of-use rancidity and antioxidant test panel for determining the freshness of chicken feed on-site at farms in less than five minutes. If successful, this work will provide a prototype, handheld rancidity test panel that is easy to use by farm workers along with a simple, rapid and robust protocol for preparing animal feed samples for analysis. To demonstrate utility, we will investigate the degree of correlation of data obtained by our prototype panel for oxidation/antioxidant content with peroxide data, one indicator of feed rancidity, obtained for the same samples using laboratory assays. We will seek to accomplish the following Technical Objectives to meet this goal:Goal 1: Develop a feed sampling and homogenization protocol that is easy to use and produces a uniform sample for testing.This facet of the project will include developing methodology for emulsifying a feed sample and preparing it for testing. We will evaluate a commercially available, high-shear emulsifying mixer as well as three high-quality household blenders. Multiple extraction media will also be formulated and evaluated during this portion of the work. We will also explore several different buffer types,additives, and other excipients to improve the extraction whichwill then be compared for their performance with a wide range of chicken feeds, including pellets, crumbles, and whole grains.Goal II: Demonstrate that dry chemistry rancidity and antioxidant test correlate directly with laboratory liquid phase assays. We will employ our commercial liquid phase rancidity and antioxidant methods, and the American Chemists' Oil Society Peroxide Value method to determine the concentration range on these analytes present in various chicken feeds, both fresh and after accelerated rancidification. Using this range of values, we will reformulate our test strip formulations to give a noticeable, robust visual color change. Laboratory scale pilot lot of strips will be manufactured and evaluated based our established protocols when the formulations are finalized.Goal III: Evaluate the correlation between point-of-use rancidity and antioxidant results with peroxide value and established measures of rancidity & palatability of chicken feeds. Establish test panel precision, accuracy, limit of detection and error.This facet of the study will determine whether, with an optimized feed homogenization protocol, and reproducible test strip assay data, our test panel can predict when a feed has become sufficiently rancid that it will most likely be rejected by chickens. The lab-based method for determining the peroxide value from extracted feed sampleswill be compared to our new rapid testvalues to determine the degree of correlation. Based on previous reports in the literatureshowing the preference of chickens for feed vs. peroxide value, we will draw conclusions as to whether our test can distinguish between feed that chickens will and will not eat. Also, the limit of detection, precision, accuracy, and percent error with respect to their liquid phase equivalents will be determined.

Martinez, Enrique
University of Bergen, Norway
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