Dietary Catalase Supplementation Alleviates Deoxynivalenol-Induced Oxidative Stress and Gut Microbiota Dysbiosis in Broiler Chickens.

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.

Effects of micronized bamboo powder on growth performance, serum biochemical indexes, cecal chyme microflora and metabolism of broilers aged 1-22 days.

Adding insoluble fiber to diet of broilers has been reported to improve intestinal health and promote growth performance. Bamboo powder is a cheap raw material with rich insoluble fiber. This study aims to explore the effects of feeding micronized bamboo powder (MBP) on growth performance, serum biochemical indexes, intestinal microflora, and metabolism of broilers. A total of 1440 1-day-old slow-growing Ephedra chickens were randomly divided into three groups considering gender and body weight: (1) Group D: feeding with basal diet without antibiotics; (2) Group E: feeding with basal diet supplemented with 5% rice bran (RB); (3) Group F: feeding with basal diet supplemented with 1% MBP. Each group involved 8 replicates feeding for 22 days, with 60 chickens per replicate. Various indexes were detected. For the growth performance, the weight gain and feed consumption ratio (G: F) of Group F supplemented with MBP is 0.57 ± 0.04, which is significantly higher than that of E group supplemented with RB (0.52 ± 0.01, P < 0.05). For the serum biochemical indexes, the glutathione peroxidase activity in Group F is significantly higher than that of Group D, while the malondialdehyde content is significantly lower than that of Group D and Group E (P < 0.05 for all). The fresh cecal chyme is taken for determination. In Group F, the α diversity index Faith_pd is significantly lower in Group F than that of Group D. The microorganism species in cecal chyme of Group F and Group E are also different. The metabolic pathways of Group F, mainly in fatty acid metabolism, amino acid metabolism and intestinal immune IgA production, were different from those of Group D and Group E. Adding 1% MBP to broiler diet can enhance the anti-oxidant capacity, improve chyme microflora, regulate the metabolism pathways responsible for intestinal fatty acids, amino acids, and immunity.

Optimisation of combi-lipases from Aspergillus niger for the synergistic and efficient hydrolysis of soybean oil.

The enzymatic properties of four lipases (A, B, C and D) from different strains of Aspergillus niger, were investigated, and a 3-factor mixture design and triangular surface analysis were performed to screen the optimal combi-lipase by observing synergistic effects. Lipases B and D differed in optimal pH, temperature and substrate specificity. A combi-lipase with 31.2% lipase B and 68.8% lipase D (w/w, equal to units of 30.36% and 69.64%) exhibited optimal hydrolytic activity on soybean oil, which exceeded the sum of the combined activities of individual lipases (P < 0.05). Free fatty acid from the hydrolyzed soybean oil indicated that the synergistic effect of the combi-lipase resulted from the different fatty acid specificities of the two lipases. Overall, combi-lipase afforded an effective route for the application of lipase enzymes to animal feeds.

Nutritional and regulatory role of branched-chain amino acids in lactation.

Optimal growth and health of suckling neonates critically depend on milk production by their mothers. In both humans and animals, branched-chain amino acids (BCAA) are not only the major components of milk proteins but are also nitrogenous precursors for the synthesis of glutamate, glutamine, alanine, and aspartate in the mammary gland. These synthetic pathways, which are initiated by BCAA transaminase, contribute to the high abundance of free and peptide-bound glutamate, glutamine, aspartate and asparagine in milk. In mammary epithelial cells, the carbon skeletons of BCAA can be partially oxidized via branched-chain alpha-ketoacid dehydrogenase to provide energy for highly active metabolic processes, including nutrient transport, protein turnover, as well as lipid and lactose syntheses. In addition, results of recent studies indicate that BCAA play regulatory roles in mammary metabolism. For example, leucine can activate the mammalian target of rapamycin cell signaling pathway to enhance protein synthesis in mammary epithelial cells. Dietary supplementation with BCAA may have great potential to enhance milk synthesis by the lactating mammary gland, thereby improving neonatal survival, growth and development.