With the widespread ban on the use of antibiotics in swine feed, alternative measures need to be sought to maintain swine health and performance. Antimicrobial peptides (AMPs) are part of the nonspecific defense system and are natural antibiotics produced by plants, insects, mammalians, and micro-organisms as well as by chemical synthesis. Due to their broad microbicidal activity against various fungi, bacteria and enveloped viruses, AMPs are a potential alternative to conventional antibiotics for use in swine production. This review focuses on the structure and mechanism of action of AMPs, as well as their effects on performance, immune function and intestinal health in pigs. The aim is to provide support for the application of AMPs as feed additives replacing antibiotics in swine nutrition.

The mycotoxin deoxynivalenol (DON), one of the most common food contaminants, primarily targets the gastrointestinal tract to affect animal and human health. This study was conducted to examine the protective function of glutamic acid on intestinal injury and oxidative stress caused by DON in piglets. Twenty-eight piglets were assigned randomly into 4 dietary treatments (7 pigs/treatment): 1) uncontaminated control diet (NC), 2) NC+DON at 4 mg/kg (DON), 3) NC+2% glutamic acid (GLU), and 4) NC+2% glutamic acid + DON at 4 mg/kg (DG). At day 15, 30 and 37, blood samples were collected to determine serum concentrations of CAT (catalase), T-AOC (total antioxidant capacity), H₂O₂ (hydrogen peroxide), NO (nitric oxide), MDA (maleic dialdehyde), DAO (diamine oxidase) and D-lactate. Intestinal morphology, and the activation of Akt/mTOR/4EBP1 signal pathway, as well as the concentrations of H₂O₂, MDA, and DAO in kidney, liver and small intestine, were analyzed at day 37. Results showed that DON significantly (P<0.05) induced oxidative stress in piglets, while this stress was remarkably reduced with glutamic acid supplementation according to the change of oxidative parameters in blood and tissues. Meanwhile, DON caused obvious intestinal injury from microscopic observations and permeability indicators, which was alleviated by glutamic acid supplementation. Moreover, the inhibition of DON on Akt/mTOR/4EBP1 signal pathway was reduced by glutamic acid supplementation. Collectively, these data suggest that glutamic acid may be a useful nutritional regulator for DON-induced damage manifested as oxidative stress, intestinal injury and signaling inhibition.

Maternal gut microflora changes dramatically during perinatal period and plays a vital role in animal health and reproductive performance. However, little is known about the microbial differences between sows with different productive capacities during perinatal period. Hence, this study explored fecal microbial diversity, composition, metabolic functions, and phenotypes differences between high productive capacity (HPC, litter size ≥ 15) and low productive capacity (LPC, litter size ≤ 7) sows during late pregnancy (LP, the third day before due date) and early stage after parturition (EAP, the third day after parturition) as well as serum biochemical indices differences after parturition. Results showed that HPC sows had lower microbial richness at LP stage and higher microbial diversity at EAP stage than LPC sows. Several genera belonging to the Prevotellaceae family exhibited higher abundance, while some genera belonging to the Ruminococcaceae family exhibited lower abundance in HPC sows compared to LPC sows at LP stage. Moreover, the relative abundance of Eubacterium_coprostanoligenes_group and Ruminococcaceae_UCG-014 in HPC sows was significantly higher than that in LPC sows at EAP stage. The predicted metabolic functions related to Lipopolysaccharide biosynthesis were significantly higher in HPC sows at LP stage. Further, HPC sows had significantly higher blood urea nitrogen (BUN) and high-density lipoprotein cholesterol (HDL-C) levels after parturition, and there were strong correlations between BUN level and the relative abundance of genera belonging to the Ruminococcaceae families. These results indicated that the HPC sows may experience greater inflammation than LPC sows at LP stage. Inflammation environment might impact health but promote parturition. The microbial differences at EAP stage might be beneficial to hemostasis and anti-inflammation, which might contribute to postpartum recovery in HPC sow.

The goal of this study was to evaluate the effects of a mixture of yeast culture, cell wall hydrolysates, and yeast extracts (collectively “yeast pro