183 Evaluation of phytogenic formulations on intestinal health and the performance of nursery pigs challenged with F18+Escherichia coli.

Abstract The objective of this study was to evaluate phytogenic formulations on intestinal health and growth performance of nursery pigs challenged with F18+Escherichia coli. Weaned pigs n = 40; initial body weight (BW) = 6.4 ± 0.1 kg at 21 d of age were individually housed and assigned to 4 dietary treatments in a randomized complete block design, with initial BW and sex as blocking factors. Basal diets were formulated following NRC (2012) and fed to pigs for 28 d in 3 phases (P1:11 d, P2:10 d and P3:7 d). Treatments were NC: basal diet, non-challenge; PC: basal diet, challenged with F18+E. coli; AV1: basal diet supplemented with 1% phytobiotic containing herbal extracts and essential oils in powder form, challenged with F18+E. coli; AV2: basal diet + 1% phytobiotic containing herbal extracts and essential oils in liquid form, challenged with F18+E. coli. Growth performance and fecal score (FS) were measured weekly. On d 7, the challenged groups were orally inoculated with F18+E. coli (2.0 × 1010), whereas unchallenged pigs received a sterile saline solution. On d 28, all pigs were euthanized to collect jejunal samples to evaluate inflammatory status, oxidative stress, and diversity and relative abundance of mucosa-associated microbiota. Data were analyzed using the MIXED procedure on SAS 9.4. During the post-challenge period, PC decrease (P 0.05) average daily gain (ADG) and average daily feed intake (ADFI) when compared with NC. The PC increased (P 0.05) FS during d 7 to 11 when compared with NC, whereas AV1 and AV2 decreased (P 0.05) FS during d 7 to 11 when compared with PC. The AV1 decreased (P 0.05) Chao1 and Shannon indexes when compared with PC. The PC increased (P 0.05) the relative abundance of Prevotellaceae, Lachnospiraceae, and Ruminococcaceae compared with NC. The AV1 reduced (P 0.05) the relative abundance of Veillonellaceae, Prevotellaceae, Lachnospiraceae and tended to reduce (P = 0.062) the relative abundance of Ruminococcaceae when compared with PC. The AV2 tended to reduce the relative abundance of Streptococcaceae (P = 0.073) and Ruminococcaceae (P = 0.074) when compared with PC. The PC increased (P 0.05) occludin and tended to increase (P = 0.096) TLR4 when compared with NC. The AV1 tended to increase (P = 0.053) protein carbonyl when compared with PC. In conclusion, F18+E. coli challenge increased FS, disrupted the mucosa-associated microbiota, increased TLR4 expression, consequently reduced growth performance of pigs. The AV1 showed promise in reducing oxidative stress during F18+E. coli challenge, seen through decreased protein carbonyl levels possibly due to alterations on mucosa-associated microbiota, although without affecting growth performance. The AV2 had a moderate impact on reducing FS and altering mucosa-associated microbiota, without effect on growth performance.