246 Effects of Feeding Thermally Processed Spray-dried Egg Whites on Growth Performance, Apparent Digestibility, and Oxidative Stress in Nursery Pigs

The objectives of this study were to determine if feeding thermally processed (TP, heated at 100°C for 120 h) spray-dried egg whites (SDEW) to nursery pigs would impact growth performance, apparent total tract digestibility (ATTD) of GE, N, and S, and oxidative stress. Thirty-two barrows, (initial BW 7.1 kg) were randomly assigned to dietary treatments with 1 pig per pen. In a preliminary study, thermally processing SDEW at 100°C for 120 h increased protein carbonyls (PC) from 6 µmol/g to 19.4 µmol/g (P ≤ 0.01). Diets included either 12% SDEW, 6% TP-SDEW plus 6% SDEW, or 12% TP-SDEW. The experiment lasted 24 d for collection of growth performance data, while plasma was collected on d 21 and liver tissue harvested on d 24 to analyze for markers of oxidative stress. Feces were collected on d 22 for measures of ATTD. Daily gain, daily feed intake, feed efficiency, and ATTD of GE were not found to be different among dietary treatments (P ≥ 0.57). In contrast, ATTD of N (P = 0.11) and S (P = 0.03) were found to increase with increasing protein oxidation in the diet. There was no change in the plasma or liver F2-isoprostanes and 8-hydroxy-2’-deoxyguanosine among dietary treatments (P ≥ 0.28). An increase in plasma PC (P = 0.02) was observed in pigs fed 12% TP-SDEW compared to pigs fed 12% SDEW and pigs fed 6% TP-SDEW. In contrast, a decrease in liver tissue PC (P = 0.04) was observed in pigs fed 6% TP-SDEW compared to pigs fed 12% SDEW and 12% TP-SDEW. These results indicate that feeding TP-SDEW does not affect growth performance, ATTD of GE, and oxidative stress as indicated by F2-isoprostanes or 8-hydroxy-2’-deoxyguanosine; but appeared to have variable effects on oxidative stress as measured by PC.