Effects of Feeding Thermally Processed Spraydried 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. [ABSTRACT FROM AUTHOR]