Micro-encapsulated essential oils and organic acids combination improves intestinal barrier function, inflammatory responses and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli F4 (K88 )

摘要

This study evaluated the effects of micro-encapsulated (protected) organic acids (OA) and essential oils (EO) combination, P(OA? ?EO), and effects of a regular blend of free acids (FA) on the growth, immune responses, intestinal barrier and microbiota of weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4 (K88 ). A total of 30 crossbred (Duroc?×?Landrace?×?Large White) weaned barrows (7.41?±?0.06?kg, 28?d old) were assigned randomly to 5 treatments: 1) non-challenged positive control (PC), 2) ETEC F4 (K88 )-challenged negative control (NC), 3) NC? ?kitasamycin at 50 mg/kg? olaquindox at 100 mg/kg? ?free acidifier (FA) at 5 g/kg, 4) NC? kitasamycin at 50 mg/kg? olaquindox at 100 mg/kg? ?P(OA? ?EO) at 1 g/kg (P1), 5) NC? ?kitasamycin at 50 mg/kg? olaquindox at 100 mg/kg? ?P(OA? ?EO) at 2 g/kg (P2). Each dietary treatment had 6 replicates of one piglet each and the study lasted for 3?wk. On d 7, pigs in NC, FA, P1 and P2 were orally dosed with 10?mL of ETEC F4 (K88 ) culture (1?×?10 9 ?CFU/mL). From d 7 to 14 after the ETEC F4 (K88 ) challenge, P1 increased gain-to-feed ratio (G:F) significantly ( P ?0.05) compared with NC and FA groups. From d 14 to 21, P2 increased the average daily gain of pigs ( P ?0.05) compared with NC and FA groups. Compared with NC, P2 reduced tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-10 concentrations ( P ?0.05) in sera collected at 4?h later after ETEC F4 (K88 ) challenge. On d 21, P1 increased occludin and zonula occludens-1 protein expression in ileum compared with NC ( P ?0.05). After this 3-wk experiment, alpha diversity of gut microbiota was decreased by P2 compared with PC, and P1 increased the relative abundance of Lactobacillus in ileum, cecum and colon ( P ?0.05). In conclusion, dietary?P(OA? ?EO) additive at 2 g/kg combined with antibiotics could improve piglet performance and attenuate inflammation, and P(OA? ?EO) additive at 1 g/kg combined with antibiotics improved intestinal barrier and increased beneficial microbiota composition after an F4 (K88 ) challenge.