Eucommia ulmoides Flavones as Potential Alternatives to Antibiotic Growth Promoters in a Low-Protein Diet Improve Growth Performance and Intestinal Health in Weaning Piglets

SIMPLE SUMMARY: Antibiotic resistance is a growing threat to the effective treatment of bacterial infections in both humans and animals, making the treatment of patients and livestock more difficult or even impossible. Eucommia ulmoides flavones (EUF), which were extracted from Eucommia ulmoides leaf, have been shown strong antioxidant properties and the inhibition of pro-inflammation in our previous studies. We found that EUF could promote growth performance, improve intestinal health, and reduce colonization of coliform bacteria and diarrhea index in weanling piglets; and this suggests that EUF may be a potential alternative to in-feed antibiotic growth promoter in pig husbandry. ABSTRACT: Eucommia ulmoides flavones (EUF) have been demonstrated to attenuate the inflammation and oxidative stress of piglets. This study aimed to test whether EUF could be used as an alternative antibiotic growth promoter to support growth performance and maintain intestinal health in weanling piglets. Weaned piglets (n = 480) were assigned into three groups and fed with a low-protein basal diet (NC), or supplementation with antibiotics (PC) or 0.01% EUF (EUF). Blood, intestinal contents, and intestine were collected on days 15 and 35 after weaning. The results showed the PC and EUF supplementations increased (p < 0.05) body weight on day 35, average daily gain and gain: feed ratio from day 15 to day 35 and day 0 to day 35, whereas decreased (p < 0.05) the diarrhea index of weanling piglets. EUF treatment increased (p < 0.05) jejunal villus height: crypt depth ratio, jejunal and ileal villus height, and population of ileal lactic acid bacteria on day 15 but decreased (p < 0.05) the population of ileal coliform bacteria on day 15 and day 35. These findings indicated the EUF, as the potential alternative to in-feed antibiotic growth promoter, could improve growth performance and intestinal morphology, and decrease colonization of coliform bacteria and diarrhea index in weanling piglets.