Quality changes in animal feed resulting from extended storage.

The objective of this study was to determine if extended storage of animal feed after autoclaving had an effect on the quality of feed which could be deleterious to experimental animals. Fresh animal feed was autoclaved each week and placed in an environmentally controlled storage room (18.5 +/- 2 degrees C with 50 +/- 5% RH). This process provided feed on a weekly basis that had a consistent storage time of 10, 74 or 130 days. Weanling male and female BALB/c and B6C3F1 mice were the test animals. The animals were housed four to a cage and were started on the experiment in two replicates separated by one week. The study was terminated after 13 weeks. Food consumption and body weights were measured weekly and serum protein levels analyzed upon termination of the study. Statistical analysis of the results showed several interactions among gender, replication and mouse genome, but no significant differences were present among treatment groups for the serum proteins or weight ratios. The animals appeared to be normal, and a histological examination of the liver showed no signs of disease or nutritional disorders. This study indicates that feed can be stored up to 130 days after autoclaving without apparent deleterious effects on animals receiving the feed.