PSIV-13 Effects of Increasing Dietary Alpha-Linolenic Acid on Nursery Pig Growth Performance and Response to Immune Challenge

Abstract

Abstract A total of 350 weanling pigs (Line 241 × 600, DNA; initially 5.8 ± 0.1 lb BW) were used in a 41-d study to evaluate growth performance and immune response of nursery pigs fed diets containing increasing levels of O3 Trial Feed, a source of omega-3 fatty acids (alpha-linolenic acid). At weaning, pigs were randomly assigned to 1 of 5 dietary treatments in a completely randomized design with 5 pigs per pen and 14 replications per treatment. The dietary treatments included increasing percentages of O3 Trial Feed (0, 1, 2, 3, and 4%). Omega-6:3 ratios for the 5 treatments within each phase were: Phase 1 (27.3:1, 11.6:1, 7.4:1, 5.4:1, 4.3:1); Phase 2 (23.0:1, 9.6:1, 6.1:1, 4.5:1, 3.6:1); and Phase 3 (24.4:1, 10.2:1, 6.5:1, 4.8:1, 3.8:1), respectively. On d 25, two pigs per pen were injected with 20 µg of Escherichia coli (E. coli) lipopolysaccharide (LPS) per kg BW and 1 pig per pen was injected with saline to serve as a control. Body temperature was recorded from the 3 pigs per pen prior to the injection (hour 0) and 2, 4, 6, and 12 h after injection. On d 25 a blood sample was collected 4 h post injection from pigs injected with the LPS challenge to determine IL-1β levels in serum. For overall growth performance, there were no differences observed in ADG, ADFI, or G:F (P > 0.05). Temperature increased at 2 h post LPS injection, then decreased as time from the LPS injection increased (main effect of time, P < 0.0001). Dietary treatment did not influence change in body temperature or IL-1β (P > 0.05). In this study, dietary alpha-linolenic acid levels did not influence growth performance or immune response to a LPS challenge.