Abstract
This study aimed to investigate the effects of functional oils on modulation of mucosa-associated microbiota, intestinal health, and growth performance of nursery pigs. Forty newly weaned pigs (20 barrows and 20 gilts) with 7.0 ± 0.5 kg body weight (BW) were housed individually and randomly allotted in a randomized complete block design with sex and initial BW as blocks. The dietary treatments were a basal diet with increasing levels (0.00, 0.50, 0.75, 1.00, and 1.50 g/kg feed) of functional oils (a blend of castor oil and cashew nutshell liquid; Oligo Basics USA LLC, Cary, NC) fed to pigs for 34 days divided in two phases (P1 for 13 days and P2 for 21 days). Growth performance was analyzed weekly. On day 34, all pigs were euthanized to collect jejunal mucosa for analyzing the mucosa-associated microbiota and intestinal health, and ileal digesta for analyzing apparent ileal digestibility. Data were analyzed using SAS 9.4. Supplementation of functional oils did not affect the overall growth performance. Increasing supplementation of functional oils reduced (p < 0.05) the relative abundance of Helicobacteraceae, whereas it increased (p < 0.05) Lactobacillus kitasatonis. Supplementation of functional oils tended (p = 0.064) to decrease protein carbonyl and increase the villus height (p = 0.098) and crypt depth (p = 0.070). In conclusion, supplementation of functional oils enhanced intestinal health of nursery pigs by increasing beneficial and reducing harmful bacteria, potentially reducing oxidative stress and enhancing intestinal morphology, without affecting overall growth performance of pigs. Supplementation of functional oils at 0.75-1.50 g/kg feed was the most beneficial to the jejunal mucosa-associated microbiota and intestinal integrity of nursery pigs.