An effect of fish food preparation by Analytical methods

Fish is an important to determine the nutrient content, fish fed to piscivorous species to ensure the animals are receiving an appropriate diet. The results of chemical analyses for nutrients can be affected by various factors including collection of a representative sample, sample preparation methodology, and laboratory and instrument variation. The objective of this project was to determine the effects of sample handling and preparation on dry matter, protein, fat and energy content in rainbow trout (Oncorhynchus mykiss). Variation among laboratories using the same preparation methods was also investigated. Five different methods of preparation were utilized: thawed pureed, frozen pureed, thawed pureed with water, ground with dry ice, and ground with liquid nitrogen. Subsamples from each preparation method were submitted to two laboratories for analyses. It was found that method of preparation does not significantly affect chemical analysis. However, variation among laboratories can be an important source of variation in analysis.