Catalase (CAT) can eliminate oxygen radicals, but it is unclear whether exogenous CAT can protect chickens against deoxynivalenol (DON)-induced oxidative stress. This study aimed to investigate the effects of supplemental CAT on antioxidant property and gut microbiota in DON-exposed broilers. A total of 144 one-day-old Lingnan yellow-feathered male broilers were randomly divided into three groups (six replicates/group): control, DON group, and DON + CAT (DONC) group. The control and DON group received a diet without and with DON contamination, respectively, while the DONC group received a DON-contaminated diet with 200 U/kg CAT added. Parameter analysis was performed on d 21. The results showed that DON-induced liver enlargement (p < 0.05) was blocked by CAT addition, which also normalized the increases (p < 0.05) in hepatic oxidative metabolites contents and caspase-9 expression. Additionally, CAT addition increased (p < 0.05) the jejunal CAT and GSH-Px activities coupled with T-AOC in DON-exposed broilers, as well as the normalized DON-induced reductions (p < 0.05) of jejunal villus height (VH) and its ratio for crypt depth. There was a difference (p < 0.05) in gut microbiota among groups. The DON group was enriched (p < 0.05) with some harmful bacteria (e.g., Proteobacteria, Gammaproteobacteria, Enterobacteriales, Enterobacteriaceae, and Escherichia/Shigella) that elicited negative correlations (p < 0.05) with jejunal CAT activity, and VH. DONC group was differentially enriched (p < 0.05) with certain beneficial bacteria (e.g., Acidobacteriota, Anaerofustis, and Anaerotruncus) that could benefit intestinal antioxidation and morphology. In conclusion, supplemental CAT alleviates DON-induced oxidative stress and intestinal damage in broilers, which can be associated with its ability to improve gut microbiota, aside from its direct oxygen radical-scavenging activity.

Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet.Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme.Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed bran-containing diet.Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet.

This study was conducted to investigate the protective effects of xylooligosaccharide (XOS) on the growth performance and intestinal health of broilers challenged by avian pathogenic Escherichia coli (APEC). A total of 144 newly hatched male Lingnan yellow-feathered broilers were randomly divided into three groups (six replicates/group): a control (CON) group, an APEC group and an XOS group (APEC-challenged broilers supplemented with 1600 mg/kg XOS). Birds in the APEC and XOS groups were orally challenged with APEC from 7 to 12 d of age. Growth performance and intestinal health-related parameters were determined on d 13 and 17. The reductions (p < 0.05) in final body weight, average daily gain and elevation (p < 0.05) in intestinal APEC colonization in challenged broilers were counteracted by the XOS addition, which also alleviated the APEC-induced reductions (p < 0.05) in jejunal goblet cell count and density in broilers on d 17. Supplementing with XOS increased (p < 0.05) jejunal villus height and crypt depth, coupled with occludin and zonula occluden-1 expression, on d 17, and diminished the change (p < 0.05) in the jejunal inflammatory cytokine expression profile in a time-dependent manner. Moreover, cecal counts of total bacteria and Lactobacillus in challenged broilers were augmented (p < 0.05) by the XOS addition, which also mitigated APEC-induced reductions (p < 0.05) in cecal acetate, butyrate and valerate concentrations in broilers on d 13 or 17. Supplementing with XOS blocked the increases (p < 0.05) in the expression of cecal E. coli virulence genes relA and ompR on d 13 along with the expression of fimH and csgA on d 17. XOS alleviated APEC-induced growth retardation and intestinal disruption in broilers partially by restraining the intestinal colonization of APEC. Furthermore, the improvements in cecal microbiota and fermentation pattern, along with attenuation of cecal E. coli virulence resulting from XOS supplementation, could also support the maintenance of intestinal health in APEC-challenged broilers.

Oxidative stress is believed to deteriorate production performance and cause substantial economic losses in commercial poultry farming. Resveratrol (RES) is a polyphenolic antioxidant that can improve intestinal barrier function and regulate gut microbiota composition. This study aimed to evaluate whether short-term (14 days) dietary resveratrol (1000–3000 mg/kg) mitigates dexamethasone (DEX)-induced oxidative stress and performance loss in yellow-feathered broilers. Two hundred and forty 52-day-old birds were assigned to five treatments (n = 8 pens × 6). Control (CON) and DEX groups received the basal diet; DR1, DR2 and DR3 were provided with the basal diet plus 1000, 2000 or 3000 mg/kg RES. During days 1–5, the DEX and RES (DR1, DR2 and DR3) groups were intraperitoneally injected with 5 mg/kg BW DEX; CON birds received saline. DEX significantly reduced average daily gain (ADG) and raised feed conversion ratio (FCR) (p < 0.05) without altering feed intake. RES at 1000–2000 mg/kg improved ADG, reduced FCR and lowered serum corticosterone and blood urea nitrogen while increasing albumin (p < 0.05). DEX elevated malondialdehyde (MDA) in liver and thigh muscle, suppressed liver catalase (CAT) activity, and suppressed thigh muscle superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and CAT activities. In serum, only SOD activity decreased. RES partially alleviated the abnormal changes in these antioxidant indices. Intestinally, DEX increased MDA, shortened villi and reduced the villus-to-crypt ratio, whereas RES partially reinstated ileal morphology, decreased MDA dose-dependently and linearly enhanced duodenal SOD activity (p < 0.05). DEX downregulated Occludin mRNA; RES upregulated Occludin and elevated ileal GPX2, SOD, CAT and PPAR-γ transcripts with a quadratic response to RES dose, while lowering duodenal CAT mRNA. Overall, short-term RES supplementation—particularly at 1000–2000 mg/kg—improves growth performance, meat quality and intestinal health of yellow-feathered broilers under DEX-induced oxidative stress by enhancing systemic and intestinal antioxidant capacity and reinforcing epithelial barrier integrity.

Salmonella enterica serovar typhimurium (S. Typhimurium) is a common Gram-negative foodborne pathogenic bacterium that causes gastrointestinal disease in humans and animals. It is well known that adhesins and invasins play crucial roles in the infection mechanism of S. Typhimurium. S. Typhimurium STM0306 has been denoted as a putative protein and its functions have rarely been reported. In this study, we constructed the STM0306 gene mutant strain of S. Typhimurium and purified the recombinant STM0306 from Escherichia coli. Deletion of the STM0306 gene resulted in reduced adhesion and invasion of S. Typhimurium to IPEC-J2, Caco-2, and RAW264.7 cells. In addition, STM0306 could bind to intestinal epithelial cells and induced F-actin modulation in IPEC-J2 cells. Furthermore, we found that STM0306 activated the nuclear factor kappa B (NF-κB) signaling pathway and increased the mRNA expression of pro-inflammatory cytokines such as IL-1β, TNF-α, as well as chemokine CXCL2, thus resulting in cellular inflammation in host cells. In vivo, the deletion of the STM0306 gene led to reduced pathogenicity of S. Typhimurium, as evidenced by lower fecal bacterial counts and reduced body weight loss in S. Typhimurium infected mice. In conclusion, the STM0306 of S. Typhimurium is an important adhesin/invasin involved in the pathogenic process and cellular inflammation of the host.

The objective of this study was to investigate the impact of exogenous catalase (CAT) on antioxidant properties, as well as on hepatic and intestinal health, in piglets exposed to Fusarium graminearum mycotoxins (FGM). Forty female weaned piglets were divided into five groups (eight replicates per group). The pre-feeding period was 3 days, followed by a 28-day experimental period. The piglets in the control (CON) group were fed a diet without FGM contamination, while those in the FGM-exposed (TOX) group were fed a diet with FGM contamination. The LCAT, MCAT, and HCAT groups received an FGM-contaminated diet supplemented with 100, 200, and 400 U/kg of CAT, respectively. The results indicated that 400 U/kg CAT supplementation inhibited (p < 0.05, linear p < 0.05, quadratic p < 0.05) the decreases in average daily gain and average daily feed intake of piglets exposed to FGM. Moreover, all doses of supplemental CAT suppressed (p < 0.05) the increases in diarrhea rate and diarrhea index of FGM-exposed piglets. Additionally, supplemental CAT reversed (p < 0.05, linear and quadratic p < 0.05 in ileal tissue, quadratic p < 0.05 in ileal chyme) the decrease in ileal tissue and increase in ileal chyme of reactive oxygen species of piglets exposed to FGM. Supplemental CAT also enhanced the activities of ileal CAT (p < 0.05, quadratic p < 0.05) coupled with hepatic superoxide dismutase and CAT (p < 0.05, linear p < 0.05, quadratic p < 0.05) and elevated (p < 0.05) the expression of ileal and hepatic antioxidation-related genes of FGM-exposed piglets. Furthermore, the CAT supplementation increased (p < 0.05) the expression of Occludin and Claudin-1 in the ileum and colon of piglets exposed to FGM. The FGM-induced increase in the genus Staphylococcus and decrease in the genus Lactobacillus in the ileum of piglets were inhibited (p < 0.05) by supplemental 400 U/kg CAT, which also modulated the metabolite profiles involved in the glycerophospholipid metabolism pathway in hepatic portal vein blood. Exogenous CAT mitigates oxidative stress induced by FGM, along with improving intestinal and hepatic health of piglets, which can be associated with its ability to enhance intestinal microbiota and regulate hepatic glycerophospholipid metabolism, aside from its direct ability to scavenge oxygen radicals. The appropriate amount of supplemental CAT was 400 U/kg.