The aim of this study was to investigate whether supplementation with chitosan (COS) could reduce diarrhea and to explore how COS alleviates intestinal inflammation in weaned pigs. Thirty pigs (Duroc×Landrace×Yorkshire, initial BW of 5.65±0.27) weaned at age 21 d were challenged with enterotoxigenic Escherichia coli during a preliminary trial period, and then divided into three treatment groups. Pigs in individual pens were fed a corn-soybean meal diet, that contained either 0 (control), 50 mg/kg chlortetracycline, or 300 mg/kg COS for 21 days. The post-weaning diarrhea frequency, calprotectin levels and TLR4 protein expression were decreased (P<0.05) in both the COS and chlortetracycline groups compared with control. Simultaneously, supplemental COS and chlortetracycline had no effect on the mRNA expression of TNF-α in the jejunal mucosa, or on the concentrations of IL-1β, IL-6 and TNF-α in serum. However, COS supplementation improved (P<0.05) the mRNA expression of IL-1β and IL-6 in the jejunal mucosa. The results indicate that supplementation with COS at 300 mg/kg was effective for alleviating intestinal inflammation and enhancing the cell-mediated immune response. As feed additives, chitosan and chlortetracycline may influence different mechanisms for alleviating inflammation in piglets.

No abstract

This study was conducted to compare the effects of adding sodium butyrate (SB), medium-chain fatty acids (MCFAs), or n-3 polyunsaturated fatty acids (n-3 PUFAs) to the diet of sows during late gestation and lactation on the reproductive performance of sows and the growth performance and intestinal health of suckling piglets. Twenty-four sows (Landrace × Large-White hybrid; third parity; 200 ± 15 kg) were randomly assigned to receive 1 of 4 diets: basal diet (control group), basal diet + 1 g SB/kg (SB group), basal diet + 7.75 g MCFA/kg (MCFA group), or basal diet + 68.2 g n-3 PUFA/kg (n-3 PUFA group). The experiment began on day 85 of gestation and ended day 22 of lactation. Colostrum samples were collected from each sow. After the experiment, blood and tissue samples were collected from 1 randomly selected piglet. The results showed that the weaning-to-estrus interval of sows in the SB, MCFA, and n-3 PUFA groups was shorter than that of sows in the control group (P < 0.05). The incidence of diarrhea in suckling piglets in the SB, MCFA, and n-3 PUFA groups was lower than that of piglets in the control group (P < 0.05). The fat, protein, IgA, IgG, and IgM concentration in colostrum from sows increased following dietary supplementation with SB, MCFA, or n-3 PUFA (P < 0.05). Comparison with the control group, the mRNA expression of claudin-1, zona occludens 1, and interleukin-10 increased in the jejunum mucosa of suckling piglets in the SB, MCFA, and n-3 PUFA groups, while that of TLR4 decreased (P < 0.05). Compared with the control group, the Chao1 and ACE indexes of microbial flora in the colon contents of piglets in the SB, MCFA, and MCFA groups increased (P < 0.05), while the relative abundance of Firmicutes, Actinobacteria, and Synergistetes decreased at the phylum level (P < 0.05). In conclusion, during late pregnancy and lactation, dietary SB supplementation had a greater effect on intestinal health and caused a greater decrease in preweaning mortality of suckling piglets than did dietary MCFA or n-3 PUFA supplementation; dietary MCFA supplementation shortened the weaning-to-estrus interval of sows to a greater extent than did dietary SB or n-3 PUFA supplementation; and dietary n-3 PUFA supplementation increased the fat and protein content in the colostrum to the greatest extent.

Sulfur amino acids (SAA), particularly methionine and cysteine, are critical for the gut to maintain its functions including the digestion, absorption and metabolism of nutrients, the immune surveillance of the intestinal epithelial layer and regulation of the mucosal response to foreign antigens. However, the metabolism of SAA in the gut, specifically the transmethylation of methionine, will result in a net release of homocysteine, which is shown to be associated with cardiovascular disease and stroke. Furthermore, the extensive catabolism of dietary methionine by the intestine or by luminal microbes may result in a decrease in nutritional efficiency. Therefore, the regulation of SAA metabolism in the gut is not only nutritionally relevant, but also relevant to the overall health and well-being. The superiority of DL-2-hydroxy-4-methylthiobutyrate to DL-methionine in decreasing homocysteine production, alleviating stress responses, and reducing the first-pass intestinal metabolism of dietary methionine may provide a promising implication for nutritional strategies to manipulate SAA metabolism and thus to improve the nutrition and health status of animals and perhaps humans.

With the rise of the Internet of Things (IoT) and fifth‐generation (5G) networks, which have led to a surge in data processing and increased data transfer time, traditional cloud computing could no longer meet the needs of workers, so edge computing has emerged. Edge computing could meet the demand for low time consumption by processing data at the edge of the network and then transmitting it to a third‐party platform. However, since the credibility of the third‐party platform is unknown which can easily leak the privacy of workers. For the transparent mechanism of blockchain, a two‐stage privacy protection mechanism based on blockchain is proposed to solve this problem. In the first stage, this paper proposes a double disturbance localized differential privacy (DDLDP) algorithm to disturb the location information of workers. In the second stage, all the sensing data are uploaded to the blockchain through edge nodes, processed by the edge cloud, and fed back to the requester. Blockchain technology not only guarantees the integrity of sensing data, but also prevents the possibility of third‐party platforms from leaking workers' privacy. Through extensive performance evaluation and comparative experiments on real data sets, the DDLDP algorithm could effectively protect the privacy of workers and has higher service quality and data availability.

In recent years, many studies have shown that the intestinal microflora has various effects that are linked to the critical physiological functions and pathological systems of the host. The intestinal microbial community is widely involved in the metabolism of food components such as protein, which is one of the essential nutrients in diets. Additionally, dietary protein/amino acids have been shown to have had a profound impact on profile and operation of gut microbiota. This review summarizes the current literature on the mutual interaction between intestinal microbiota and protein/amino acid metabolism for host mucosal immunity and health.

Synthetic porcine beta-defensin-2 (pBD-2) was tested as an alternative to antimicrobial growth-promoters in pig production. Thirty 21-day weaned piglets were challenged with enterotoxigenic Escherichia coli, and orally dosed with either sterile water (CON), pBD-2 (BD) or neomycin sulphate (NS) twice daily for 21 days. pBD-2 and NS led to higher growth performance, jejunum villus height and increased expression of insulin-like growth factor-I compared with the CON group (P < 0.05). Hemolytic E. coli scores from rectal swabs, and copy numbers of E. coli, Bacteroides fragilis and Streptococcus in the cecal digesta of the BD- or NS-treated piglets were lower than those in the CON group (P < 0.05). Messenger RNA levels of toll-like receptor 4, tumor necrosis factor-α, interleukin (IL)-1β, and IL-8 in the jejunum mucosa of the BD and NS groups were lower than those in the CON group (P < 0.05). Copy numbers of Lactobacilli and Bifidobacteria in the cecal digesta of the BD group were higher than those of the CON and NS groups (P < 0.05). Therefore, pBD-2 has antimicrobial activity in piglets, and it can improve growth performance, reduce inflammatory cytokine expression and affect intestinal morphological indices in the same way as probiotics. © 2015 Japanese Society of Animal Science.

Bovine lactoferrampin (LFA) and bovine lactoferricin (LFC) are two antimicrobial peptides located in the N(1) domain of bovine lactoferrin. The bactericidal activity of the fused peptide LFA-LFC is stronger than that of either LFA or LFC. The high cost of peptide production from either native digestion or chemical synthesis limits the clinical application of antimicrobial peptides. The expression of recombinant peptides in yeast may be an effective alternative. In the current study, the expression, purification, and antibacterial activity of LFA-LFC using the Pichia pastoris expression system are reported. The linearized expression vector pPICZaA-LFA-LFC was transformed into P. pastoris KM71 by electroporation, and positive colonies harboring the target genes were screened out and used for fermentation. The recombinant LFA-LFC peptide was purified via two-step column chromatography and identified by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results indicate that P. pastoris is a suitable system for secreting LFA-LFC. The fermentation supernate and the purified LFA-LFC show high antimicrobial activities. The current study is the first to report on the expression and purification of LFA-LFC in P. pastoris and may have potential practical applications in microbial peptide production.