Abstract

Simple SummaryWeaning stress causes retarded growth, gut disorder and dysfunction, severe diarrhea and higher mortality in weaned piglets. Antibiotic growth promoters (AGP) have been conventionally used to alleviate the negative effects of weaning stress. However, the long-term use of AGP leads to various adverse effects, such as antimicrobial resistance and food drug residues, and threatens public safety. Therefore, AGP should be replaced with residue-free, pollution-free and toxin-free alternatives because several countries and regions have banned the use of AGP in the feed industry. This study investigates the effects of an encapsulated organic acid and essential oil mixture (OAEO) on the growth performance, immuno-antioxidant capacity and intestinal health of weaned piglets. The results reveal that OAEO as an alternative to AGP improved the growth performance, immuno-antioxidant status and intestinal health of weaned piglets partly by activating the Nrf2 signaling pathway and suppressing the TLR4/NF-κB signaling pathway.AbstractThis study investigates the effects of an encapsulated organic acid and essential oil mixture (OAEO) on the growth performance, immuno-antioxidant capacity and intestinal health of weaned piglets. In total, 120 weaned piglets (23 days of age; 6.96 ± 0.08 kg) were randomly allotted to four treatments (six replicates/group; five piglets/replicate): the control group (CON) was fed the basal diet (BD), the antibiotic growth promoters group (AGP) received the BD with 20 mg/kg colistin sulphate and 10 mg/kg bacitracin zinc, and OAEO1 and OAEO2 were fed the BD with 1000 mg/kg and 2000 mg/kg OAEO, respectively. The trial lasted 21 days and then one piglet per replicate was selected for sample collection. OAEO increased the average daily gain, spleen index, serum interleukin (IL)-10, immunoglobulin (Ig) G and IgA levels; serum superoxide dismutase a