Effects of dietary supplementation of myristic acid on jejunal mucosa-associated microbiota, mucosal immunity, and growth performance of nursery pigs

The objective of this study was to investigate the effects of myristic acid on jejunal mucosal microbiota, mucosal immunity, and growth performance of nursery pigs. Thirty-six pigs (6.6 +/- 0.4 kg of body weight) were assigned to three treatments (n = 12) for 35 d in three phases: (NC) basal diet; (PC) NC + bacitracin; and (MA) NC + myristic acid compound. Pigs were euthanized to collect jejunal mucosa, jejunal tissues, and ileal digesta. The PC increased (p < 0.05) the relative abundance (RA) of Lactobacillus spp., and Bifidobacterium boum than the NC group. The MA increased (p < 0.05) RA of Bifidobacterium dentium and Megasphaera spp. than the NC group. The PC tended to decrease IL-8 (p = 0.053) and protein carbonyl (p = 0.075) whereas IgG (p = 0.051) and IL-8 (p = 0.090) in jejunal mucosa were decreased by the MA. The PC increased (p < 0.05) the villus height to crypt depth ratio than the NC group. Both bacitracin and myristic acid improved the intestinal health and growth performance of nursery pigs. Effects of bacitracin were rather immediate whereas the effects of myristic acid were obtained after a 3-week feeding.