Feeding of oxidized fats to broilers and swine: Effects on enterocyte turnover, hepatocyte proliferation and the gut associated lymphoid tissue

This study was designed to examine the cellular effects of feeding oxidized fats to broilers in the presence or absence of the antioxidant Santoquin(R). Although bird performance may be affected by the addition of rancid feed ingredients in the diet, little is known about the mechanism responsible for performance effects. In this study, gain, feed conversion and hematocrit were negatively affected by the feeding of oxidized fat (4 meq kg(-1) diet). All these effects were ameliorated by the inclusion of ethoxyquin in the diet at 125 ppm. Results indicated that the gastrointestinal epithelium responded to oxidant stress with an increase in cell turnover. Hepatic cell proliferation increased. The gut associated immune system was also affected. Although plasma cell numbers were not affected based on histology, the concentration of immunoglobulin in the intestinal tissue appeared to be lower. These indicators of oxidative stress may be related to the poor performance seen in animals fed unstabilized diets containing oxidized ingredients.