Eco-friendly and efficient strategies for eliminating cadmium (Cd) phytoremediation plant residues are needed. The present study investigated the feasibility of feeding Cd accumulator maize to beef cattle. In total, 20 cattle at 6 months of age were selected and randomly allocated into two groups fed with 85.82%(fresh basis) Cd accumulator maize (CAM) or normal maize (control [Con]) silage diets for 107 d. Feeding CAM did not affect the body weight (P = 0.24), while it decreased feed intake and increased feed efficiency of beef cattle (P < 0.01). Feeding CAM increased serum concentrations of immunoglobulin A and G, complement 3 and 4, blood urea nitrogen, and low-density lipoprotein cholesterol, decreased serum concentrations of interleukin-6 and lipopolysaccharide (P < 0.05), and caused wider lumens in the renal tubules. The Cd residue in meat was 7μg/kg beyond the restriction for human food. In the muscle, the unsaturated fatty acids (t11C18∶1 and C20∶4), Lys, Arg, Pro, and Cys were decreased, while the saturated fatty acids (C10∶0, C12∶0, and C17∶0) and Leu were increased (P < 0.05). Therefore, at the current feeding level, phytoremediation maize increased the feed efficiency of beef cattle, but did present risks to cattle health and production safety, and decreased the meat nutrition and flavor. Further research must be performed to determine whether a lower proper dose of phytoremediation maize and an appropriate feeding period may be possible to ensure no risk to cattle health and the supply of safe meat for humans.

Beta-hydroxybutyric acid (BHBA), as one of the main metabolic ketones in the rumen epithelium, plays critical roles in cellular growth and metabolism. The ketogenic capacity is associated with the maturation of rumen in young ruminants, and the exogenous BHBA in diet may promote the rumen development. However, the effects of exogenous BHBA on rumen remain unknown. This is the first study to investigate the mechanisms of BHBA on gene expression and metabolism of rumen epithelium using young goats as a model through multi-omics techniques. Thirty-two young goats were divided into control, low dose, middle dose, and high dose groups by supplementation of BHBA in starter (0, 3, 6, and 9g/day, respectively). Results demonstrated the dietary of BHBA promoted the growth performance of young goats and increased width and length of the rumen papilla (P < 0.05). Hub genes in host transcriptome that were positively related to rumen characteristics and BHBA concentration were identified. Several upregulated hub genes including NDUFC1, NDUFB4, NDUFB10, NDUFA11 and NDUFA1 were enriched in the gene ontology (GO) pathway of nicotinamide adenine dinucleotide (NADH) dehydrogenase (ubiquinone) activity, while ATP5ME, ATP5PO and ATP5PF were associated with ATP synthesis. RT-PCR revealed the expression of genes (HMGCS2, BDH1, SLC16A3, etc.) associated with lipolysis increased significantly by BHBA supplementation (P < 0.05). Metabolomics indicated that some metabolites such as glucose, palmitic acid, cortisol and capric acid were also increased (P < 0.05). This study revealed that BHBA promoted rumen development through altering NADH balance and accelerating lipid metabolism, which provides a theoretical guidance for the strategies of gastrointestinal health and development of young ruminants.

Copper (Cu) is a trace element, essential for fish growth. In the current study, in addition to growth performance, we first explored the effects of Cu on collagen synthesis and myofiber growth and development in juvenile grass carp (Ctenopharyngodon idella). A total of 1080 fish (11.16 ± 0.01g) were randomly divided into 6 treatments (3 replicates per treatment) to receive five doses of organic Cu, which were Cu citrate (CuCit) at 0.99 (basal diet), 2.19, 4.06, 6.15, and 8.07mg/kg, and one dose of inorganic Cu (CuSO₄·5H₂O at 3.15mg/kg), for 9 weeks. The results showed appropriate Cu level (4.06mg/kg) enhanced growth performance, improved nutritional Cu status, and downregulated Cu-transporting ATPase 1 mRNA levels in the hepatopancreas, intestine, and muscle of juvenile grass carp. Meanwhile, collagen content in fish muscle was increased after Cu intake, which was probably due to the following pathways: (1) activating CTGF/TGF-β1/Smads signaling pathway to regulate collagen transcription; (2) upregulating of La ribonucleoprotein domain family 6 (LARP6) mRNA levels to regulate translation initiation; (3) increasing proline hydroxylase, lysine hydroxylase, and lysine oxidase activities to regulate posttranslational modifications. In addition, optimal Cu group increased myofiber diameters and the frequency of myofibers with diameter >50μm, which might be associated with upregulation of cyclin B, cyclin D, cyclin E, proliferating cell nuclear antigen, myogenic determining factor (MyoD), myogenic factor 5, myogenin (MyoG), myogenic regulatory factor 4 and myosin heavy chain (MyHC) and downregulation of myostatin mRNA levels, increasing protein levels of MyoD, MyoG and MyHC in fish muscle. Finally, based on percentage weight gain (PWG), serum ceruloplasmin (Cp) activity and collagen content in fish muscle, Cu requirements were determined as 4.74, 4.37 and 4.62mg/kg diet (CuCit as Cu source) of juvenile grass carp, respectively. Based on PWG and Cp activity, compared to CuSO₄·5H₂O, the efficacy of CuCit were 131.80% and 115.38%, respectively. Our findings provide new insights into Cu supplementation to promote muscle growth in fish, and help improve the overall productivity of aquaculture.

Enterotypes, which are defined as bacterial clusters in the gut microbiome, have been found to have a close relationship to host metabolism and health. However, this concept has never been used in the rumen, and little is known about the complex biological relationships between ruminants and their rumen bacterial clusters. In this study, we used young goats (n = 99) as a model, fed them the same diet, and analyzed their rumen microbiome and corresponding bacterial clusters. The relationships between the bacterial clusters and rumen fermentation and growth performance in the goats were further investigated. Two bacterial clusters were identified in all goats: the P-cluster (dominated by genus Prevotella, n = 38) and R-cluster (dominated by Ruminococcus, n = 61). Compared with P-cluster goats, Rcluster goats had greater growth rates, concentrations of propionate, butyrate, and 18 free amino acids and proportion of unsaturated fatty acids, but lower acetate molar percentage, acetate to propionate ratio, and several odd and branched chain and saturated fatty acids in rumen fluid (P < 0.05). Several members of Firmicutes, including Ruminococcus, Oscillospiraceae NK4A214 group, and Christensenellaceae R-7 group were significantly higher in the R-cluster, whereas Prevotellaceae members, such as Prevotella and Prevotellaceae UCG-003, were significantly higher in P-cluster (P < 0.01). Co-occurrence networks showed that R-cluster enriched bacteria had significant negative correlations with P-cluster enriched bacteria (P < 0.05). Moreover, we found the concentrations of propionate, butyrate and free amino acids, and the proportions of unsaturated fatty acids were positively correlated with R-cluster enriched bacteria (P < 0.05). The concentrations of acetate, acetate to propionate ratio, and the proportion of odd and branched chain and saturated fatty acids were positively correlated with P-cluster enriched bacteria (P < 0.05). Overall, our results indicated that rumen bacterial clusters can influence rumen fermentation and growth performance of young goats, which may shed light on modulating the rumen microbiome in early life to improve the growth performance of ruminant animals.

An accurate estimation of net energy (NE) of wheat bran is essential for precision feeding of sows. However, the effects of inclusion level on NE of wheat bran have not been reported. Inclusion level was hypothesized to impact NE of wheat bran by regulating gut microbiota and partitioning of heat production. Therefore, twelve multiparous sows (Yorkshire × Landrace; 2 to 4 parity) were assigned to a replicated 3 × 6 Youden square with 3 successive periods and 6 diets in each square. The experiment included a corn-soybean meal diet (WB0) and five diets including 9.8% (WB10), 19.5% (WB20), 29.2% (WB30), 39.0% (WB40) and 48.7% wheat bran (WB50), respectively. Each period included 6 d of adaptation to diets followed by 6 d for heat production measurement using open-circuit respiration chambers. Compared with other groups, WB30, WB40, and WB50 enriched different fiber-degrading bacteria genera (P < 0.05). Apparent total tract digestibility of neutral detergent fiber and acid detergent fiber of wheat bran were greater in WB30 and WB40 (P < 0.05). Physical activity (standing and sitting) decreased as inclusion level increased (P = 0.04), which tended to decrease related heat production (P = 0.07). Thermic effect of feeding (TEF) was higher in WB50 than other treatments (P < 0.01). Metabolizable energy of wheat bran was similar among treatment groups (except for WB10). NE of wheat bran conformed to a quadratic regression equation with inclusion level (R² = 0.99, P < 0.01) and peaked at an inclusion level of 35.3%. In conclusion, increasing inclusion level decreased energy expenditure of sows on physical activity and promoted growth of fiber-degrading bacteria, which improved energy utilization of fiber. Fermentation of wheat bran fiber by Prevotellaceae_UCG-003 and norank_f__Paludibacteraceae might increase TEF. Consequently, sows utilized energy in wheat bran most efficiently at an inclusion level of 35.3%.

An 8-week feeding trial was conducted in Pacific white shrimp (Litopenaeus vannamei) to evaluate the effects of dietary choline supplementation on choline transport and metabolism, hepatopancreas histological structure and fatty acid profile, and regulation of lipid metabolism. Six isonitrogenous and isolipidic diets were formulated to contain different choline levels of 2.91 (basal diet), 3.85, 4.67, 6.55, 10.70 and 18.90g/kg, respectively. A total of 960 shrimp (initial weight, 1.38 ± 0.01g) were distributed randomly into twenty-four 250-L cylindrical fiber-glass tanks, with each diet assigned randomly to 4 replicate tanks. The results indicated that dietary choline significantly promoted the deposition of choline, betaine and carnitine (P < 0.05). The diameters and areas of R cells, total lipid and triglyceride contents in hepatopancreas, and triglyceride and non-esterified fatty acid contents in hemolymph were negatively correlated with dietary choline level. The contents of functional fatty acids in hepatopancreas, the activity of acetyl-CoA carboxylase (Acc), and the mRNA expression of fas, srebp and acc were highest in shrimp fed the diet containing 4.67g/kg choline, and significantly higher than those fed the diet containing 2.91g/kg, the lowest level of choline (P < 0.05). The number of R cells, content of very lowdensity lipoprotein (VLDL), activities of carnitine palmitoyl-transferase (Cpt1), lipoprotein lipase and hepatic lipase, and the mRNA expression levels of cpt1, fabp, fatp, ldlr, and ampk in hepatopancreas increased significantly as dietary choline increased (P < 0.05). In addition, hepatopancreas mRNA expression levels of ctl1, ctl2, oct1, badh, bhmt, ck, cept, and cct were generally up-regulated as dietary choline level increased (P < 0.01). In conclusion, dietary choline promoted the deposition of choline and its metabolites by up-regulating genes related to choline transport and metabolism. Moreover, appropriate dietary choline level promoted the development of hepatopancreas R cells and maintained the normal accumulation of lipids required for development, while high dietary choline not only promoted hepatopancreas lipid export by enhancing VLDL synthesis, but also promoted fatty acid β-oxidation and inhibited de novo fatty acid synthesis by activating the Ampk/Srebp signaling pathway. These findings provided further insight and understanding of the mechanisms by which dietary choline regulated lipid metabolism in L. vannamei.

Current methods for feed formulation are based on minimizing costs, not maximizing profits. Complex models of bird growth and reproduction as functions of genetic, feed and other environmental variables are being developed, but their adaptation has been slow. The development of profit maximizing models will evolve to center on the production functions of broilers and layers. The production functions are the relationship between the value of products (mainly meat and eggs) and the cost of feed. The production function is the tool used to maximize profits subject to all the various inputs, not just feed or nutrition. The production function is subject to the law of diminishing returns. The most profitable output levels are those where the marginal value (price) of the meat or eggs is just equal to the marginal cost of the inputs including feed, housing, processing and all other costs. Anything that affects the production function, bird genetics, feed quality, housing and environment, will be considered to maximize profits for the poultry firm. The profit maximizing models of poultry firms will improve as various technical improvements are made: metabolizable energy to describe ingredients will evolve to net energy systems that consider that the heat production (and therefore energetic efficiency) of broilers is different depending on the ingredients used to formulate the feed and the environmental temperatures under which they are reared. Amino acid needs will include a method to find the birds' needs for the nonessential amino acids. "Digestible" amino acid assays will differentiate between digestion and absorption to best balance various sources. The carbohydrate fractions of feed ingredients will be determined to optimize the use of exogenous enzymes. The value of meat and egg co-products will reduce overall costs (e.g., organic fertilizer for crop enhancement). Future profit maximizing production models will be ever evolving processes where field conditions and results are continually being utilized to re-calibrate the technical models so that the management team can use them with cost and return projections to decide on the best choices of inputs and outputs.

Enhancing hepatic gluconeogenesis is one of the main modes of meeting the glucose requirement of dairy cows. This study attempted to determine whether the gluconeogenesis precursor propionate had an effect on the expression of the main genes involved in gluconeogenesis in calf hepatocytes and elucidate the associated mechanisms. Calf hepatocytes were obtained from 5 healthy calves (1d old; 30 to 40kg) and exposed to 0-, 1-, 2.5-, or 5-mM sodium propionate (NaP), which is known to promote the expression of genes involved in the gluconeogenesis pathway, including fructose 1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase. With regard to the underlying mechanism, propionate promoted the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha, hepatocyte nuclear factor 4, and forkhead box O1 (transcription factors that regulate the expression of hepatic gluconeogenic genes) by promoting mammalian target of rapamycin complex 1 (mTORC1), but inhibiting mTORC2 activity (P < 0.01). We also established a model of palmitic acid (PA)-induced hepatic injury in calf hepatocytes and found that PA could inhibit the gluconeogenic capacity of calf hepatocytes by suppressing the expression of gluconeogenic genes, inhibiting mTORC1, and promoting the activity of mTORC2 (P < 0.01). In contrast, NaP provided protection to calf hepatocytes by counteracting the inhibitory effect of PA on the gluconeogenic capacity of calf hepatocytes (P < 0.05). Collectively, these findings indicate that NaP enhances the gluconeogenic capacity of calf hepatocytes by regulating the mTOR pathway activity. Thus, in addition to improving the glucose production potential, propionate may have therapeutic potential for the treatment of hepatic injury in dairy cows.

Selenium nanoparticles (SeNPs) are proposed as a safer and more effective selenium delivery system than sodium selenite (Na₂SeO₃). Here, we investigated the effects of replacing dietary Na₂SeO₃ with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of early-weaned piglets. Seventy-two piglets (Duroc × Landrace × Large Yorkshire) weaned at 21d of age were divided into the control group (basal diet containing 0.3mg Se/kg from Na₂SeO₃) and SeNPs group (basal diet containing 0.3mg Se/kg from SeNPs) during a 14-d feeding period. The results revealed that SeNPs supplementation increased the average daily gain (P = 0.022) and average daily feed intake (P = 0.033), reduced (P = 0.056) the diarrhea incidence, and improved (P = 0.013) the feed conversion ratio compared with Na₂SeO₃. Additionally, SeNPs increased jejunal microvilli height (P = 0.006) and alleviated the intestinal barrier dysfunction by upregulating (P < 0.05) the expression levels of mucin 2 and tight junction proteins, increasing (P < 0.05) Se availability, and maintaining mitochondrial structure and function, thereby improving antioxidant capacity and immunity. Furthermore, metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis, secretion and action of parathyroid hormone, proximal tubule bicarbonate reclamation and tricarboxylic acid cycle. Moreover, SeNPs increased (P < 0.05) the abundance of Holdemanella and the levels of acetate and propionate. Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism. Overall, replacing dietary Na₂SeO₃ with biogenic SeNPs could be a potential nutritional intervention strategy to prevent early-weaning syndrome in piglets.

This study was to evaluate the potential of a host-associated Bacillus velezensis as a probiotic for hybrid yellow catfish (Pelteobagrus fulvidraco ♂ × Pelteobagrus vachelli ♀). Diets (B0 to B5) containing 0, 0.90 × 10⁸, 0.80 × 10⁹, 0.85 × 10¹⁰, 0.90 × 10¹¹, 0.83 × 10¹² CFU/kg B. velezensis YFI-E109 were fed to the fish with initial weight (3.07 ± 0.08g) in a recirculating aquaculture system for six weeks with three replicates, respectively. Probiotic effects were analyzed based on growth, body composition, liver and gut morphology, gut microbiome, and liver metabolome. Analysis of the bacterial genome has shown that the most abundant genes in B. velezensis YFI-E109 were distributed in carbohydrate and amino acid metabolism. Fish in groups B3 and B4 had better growth performance, and higher intestinal amylase (AMS) and lipase (LPS) activities compared with other groups (P < 0.05). Fish in groups B0 and B5 showed significant liver damage, while this status improved in group B3. The liver malondialdehyde (MDA) content in group B3 was lower than that in other groups (P < 0.05). The abundance of Mycoplasma, Ralstonia and Acinetobacter was significantly reduced in B3 and B5 compared to B0. The amino acid and carbohydrate metabolism pathways were enriched in group B3 compared with group B0. In conclusion, dietary B. velezensis YFI-E109 supplementation has the potential to improve growth, liver metabolism, and liver and gut health, and reshape the gut microbiome of hybrid yellow catfish. Excessive B. velezensis YFI-E109 reduced the prebiotic effects. The recommended dietary supplementation of B. velezensis YFI-E109 is 0.31 × 10¹⁰ to 0.77 × 10¹¹ CFU/kg for hybrid yellow catfish according to the quadratic regression method by plotting specific growth rate (SGR), feed conversion ratio (FCR), MDA and activities of AMS against dietary B. velezensis YFI-E109 levels.

It has been reported that selenium (Se) can reduce hepatopancreas lipid accumulation induced by high-fat diet. However, its mechanism is still unknown. This study aims to investigate the specific mechanisms by which Se alleviates high-fat diet-induced lipid accumulation. Grass carp were fed control diet (4.8%lipid, Con), high-fat diet (8.8% lipid, HFD) or HFD supplemented with 0.3mg/kg nano-Se (HSe0.3) for 10 weeks. Growth performance, Se deposition, lipid accumulation, hepatic ultrastructure, and gene and protein expression levels associated with autophagy were examined. Furthermore, oleic acid (OA) was used to incubate the grass carp hepatocytes (L8824) for 24 h, and then the L8824 were incubated with sodium selenite in presence or absence of an autophagy inhibitor for 24 h. L8824 was analyzed for triglyceride concentration, immunofluorescence, and gene and protein expression levels associated with autophagy. We found that dietary nano-Se improved the growth of fish fed HFD and also decreased hepatosomatic index and intraperitoneal fat ratio of fish fed HFD (P < 0.05). HFD significantly increased hepatopancreas lipid accumulation and decreased autophagic activity (P < 0.05). Treatment of grass carp fed HFD with nano-Se decreased lipid accumulation and restored hepatic autophagy (P < 0.05). In vitro, Se (100 mM sodium selenite) obviously activated autophagy in L8824 incubated with OA, and consequently reduced the lipid accumulation induced by OA (P < 0.05). Furthermore, using pharmacological inhibition (chloroquine) of the autophagy greatly diminished the beneficial effects of Se on alleviating OA-induced lipid accumulation and increased the co-localization of lipid droplets with autophagosome (P < 0.05), which indicated that Se increased autophagic flux. In conclusion, these results suggest that Se alleviates HFD-induced hepatopancreas lipid accumulation by activating lipophagy.

This experiment was to evaluate the influence of sodium butyrate (SB) addition on milk production, ruminal fermentation, nutrient digestion, and the development and metabolism regulation of the mammary gland in dairy cows. Forty Holstein dairy cows averaging 710 ± 18.5kg body weight, 72.8 ± 3.66d in milk (DIM), and 41.4 ± 1.42kg/d milk production were divided into four treatments blocked by DIM and milk production. Treatments were control group, low SB, medium SB, and high SB with 0, 100, 200 and 300g/d of SB addition per cow, respectively. The study lasted for 105d. Production of milk, milk protein and lactose quadratically increased (P < 0.05), while fat-corrected milk, energycorrected milk and milk fat yields linearly increased (P < 0.05) with increasing SB addition. The digestibility of dietary dry matter, organic matter, and crude protein linearly increased (P < 0.05), whereas the digestibility of ether extract, neutral detergent fibre, and acid detergent fibre quadratically increased (P < 0.05). Ruminal pH quadratically decreased (P = 0.04), while total volatile fatty acids (VFA) quadratically increased (P = 0.03) with increasing SB addition. The acetic acid to propionic acid ratio increased (P = 0.03) linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage. Ruminal enzymatic activity of carboxymethyl-cellulase and α-amylase, populations of total bacteria, total anaerobic fungi, total protozoa, Ruminococcus albus, R. flavefaciens, Butyrivibrio fibrisolvens, Fibrobacter succinogenes, and Ruminobacter amylophilus linearly increased (P < 0.05). Blood glucose, urea nitrogen, and non-esterified fatty acids linearly decreased (P < 0.05), while total protein concentration linearly increased (P = 0.04). Moreover, the addition of SB at 200 g/d promoted (P < 0.05) mRNA and protein expression of PPARγ, SREBF1, ACACA, FASN, SCD, CCNA2, CCND1, PCNA, Bcl-2, GPR41, and the ratios of p-Akt/Akt and p-mTOR/mTOR, but decreased (P < 0.05) mRNA and protein expressions of Bax, caspase-3, and caspase-9. The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation, nutrient digestion, gene and protein expressions concerned with milk fat synthesis and mammary gland development.

This study aimed to investigate the effects of dietary supplementation of underfed Hu ewes from d 35 to 110 of gestation with either rumen-protected L-arginine (RP-Arg) or N-carbamylglutamate (NCG) on placental amino acid (AA) transport, angiogenic gene expression, and steroid anabolism. On d 35 of gestation, 32 Hu ewes carrying twin fetuses were randomly divided into four treatment groups, each consisting of eight ewes, and were fed the following diets: A diet providing 100% of NRC's nutrient re-quirements for pregnant ewes (CON); A diet providing 50% of NRC's nutrient requirements for pregnant ewes (RES); RES diet plus 5g/d NCG (RES + NCG); or RES diet plus 20g/d RP-Arg (RES + ARG). On the d 110 of pregnancy, blood samples were taken from the mother, and samples were collected from type A cotyledons (COT; the fetal portions of the placenta). The levels of 17β-estradiol and progesterone in the maternal serum and both the capillary area density (CAD) and capillary surface density (CSD) in type A COT were decreased in response to Arg or NCG supplementation when compared to the RES group. The concentrations of arginine, leucine, putrescine and spermidine in type A COT were higher (P < 0.05) in the RES + ARG or RES + NCG group than in the RES group. The mRNA expression levels of inducible nitric oxide synthase (iNOS) and solute carrier family 15, member 1 (SLC15A1) were increased (P < 0.05) while those of progesterone receptor (PGR) and fibroblast growth factor 2 (FGF2) were decreased in type A COT by supplementation with either NCG or RP-Arg compared to the RES group. The results suggest that providing underfed pregnant ewes from d 35 to 110 of gestation with a diet supplemented with NCG or RP-Arg improves placental AA transport, and reduces the expression of angiogenic growth factor genes and steroid anabolism, leading to better fetal development.

Previous studies on porous or nano particles zinc oxide (ZnO) in the piglets have mainly focused on growth performance and intestinal inflammation, but have scarcely explored the efficacy on gut microbiota. In addition, the efficacy of nano particles ZnO, which is related to its product quality, remains undefined. This study aimed to determine the efficacy of dietary 500mg/kg porous or nano particles ZnO on the growth performance and gut microbiota of the weaned piglets. A total of 128 weaned piglets were randomly assigned to the dietary groups: NC (basal diet), PC (basal diet + 3,000mg/kg conventional ZnO), 500HiZ (basal diet + 500mg/kg porous particles ZnO), and 500ZNP (basal diet + 500mg/kg nano particles ZnO). Compared with the NC diet group, both 500HiZ and 500ZNP increased (P < 0.05) average daily feed intake (1 to 28d) and average daily gain (1 to 28d), and the 500ZNP tended to decrease feed to gain ratio (F:G ratio, 1 to 28 d) (P = 0.09). Both 500HiZ and 500ZNP decreased crypt depth of the ileum and increased claudin-2 in the duodenum and zonula occludens-1 in the ileum (P < 0.05). Moreover, both 500HiZ and 500ZNP decreased IL-1β and tumor necrosis factor-a (TNF-a) in the jejunum and decreased TNF-α and IL-6 in the ileum (P < 0.05). Both 500HiZ and 500ZNP increased microbial β-diversity index in the ileum and microbial α-diversity indices in the colon of piglets (P < 0.05). The probiotic genera Coprococcus (500ZNP) and Blautia (500HiZ) were positively correlated with the F:G ratio (1 to 28 d) in colon of piglets (P < 0.05). In addition, 500HiZ promoted mitochondrial fusion protein 1 (MFN1) and zinc transporter-1 (ZnT-1) in the jejunum (P < 0.05), whilst 500ZNP decreased MFN1 in the jejunum and ZnT-1 in the ileum (P < 0.05). In summary, both 500HiZ and 500ZNP improved the growth performance of piglets, which is likely via the genera Blautia and Coprococcus, respectively. Both 500HiZ and 500ZNP improved barrier function and inflammation of the intestine, and 500HiZ achieved better efficacy than 500ZNP on intestine mitochondrial functions.

Arecoline is an alkaloid with important pharmacological effects in the plant areca nut, which has been demonstrated to be an agonist of muscarinic receptors (M receptor). This study explored the influences of dietary arecoline on growth performance, intestinal digestion and absorption abilities, antioxidant capacity, and the apical junction complex (AJC) of adult grass carp (Ctenopharyngodon idella). Adult grass carp (608 to 1512g) were fed at 6 graded levels of dietary arecoline (0, 0.5, 1.0, 1.5, 2.0, and 2.5mg/kg diet) for 9 weeks. The results suggested that appropriate dietary supplementation of arecoline (1.0mg/kg) increased growth parameters and intestinal growth in adult grass carp (P < 0.05), enhanced digestion and absorption capacities (P < 0.05), up-regulated muscarinic receptor 3 (M3) mRNA level (P < 0.05), increased the content of neuropeptide fish substance P (P < 0.05), improved antioxidant capacity by activating the Keap1a/Nrf2 signaling pathway (P < 0.05), reduced intestinal mucosal permeability (P < 0.05), and increased mRNA levels of tight junction (TJ) and adherent junction AJ-related proteins in fish by inhibiting the RhoA/ROCK signaling pathway (RhoA/ROCK/MLCK/NMII) (P < 0.05). In addition, the appropriate arecoline supplementation for adult grass carp was determined to be 1.20, 1.21, 1.07, and 1.19mg/kg based on percentage weight gain, lipase activity, serum diamine oxidase, and protein carbonyl, respectively. Overall, to the best of our knowledge, we investigated for the first time the effects and possible mechanisms of dietary arecoline on intestinal digestive and absorptive capacities and structural integrity in fish and evaluated the appropriate level of supplementation.

This study aimed to determine the effects of tributyrin on growth performance, gastrointestinal tract development, ruminal bacteria and volatile fatty acid (VFA) formation. Thirty healthy weaned Small-Tailed Han female lambs at 3 months old with BW 27.5 ± 4.1kg (mean ± SD) were randomly assigned to five groups of six lambs each, and each group received tributyrin at 0, 0.5, 1.0, 2.0 and 4.0g/kg in feed. Weights were measured before the start and end of the study. After 15d adaptation, DMI, feed, faeces and urine were recorded every week. Lambs were sacrificed at d 75. Compared to lambs fed no tributyrin, lambs fed 4.0g/kg tributyrin had higher average daily BW gain (P = 0.04) and DMI (P < 0.01). Tributyrin reduced nitrogen (P < 0.01), Ca (P < 0.01) and P (P < 0.01) losses derived from faeces and urine. The mostly important, tributyrin increased dorsal sac thickness (P < 0.01), papillae length (P = 0.04) and width (P < 0.01), ventral sac papillae length (P < 0.01) and width (P < 0.01), caudodorsal blind sac thickness (P = 0.02), papillae length (P < 0.01) and width (P < 0.01). Furthermore, tributyrin increased thicknesses of both the duodenum (P < 0.01) and ileum (P = 0.01), and villus heights of the duodenum (P = 0.01), ileum (P < 0.01), jejunum (P < 0.01) and caecum (P = 0.02), but tributyrin decreased duodenal (P < 0.01) and caecal crypt depths (P < 0.01). Tributyrin reduced rumen pH (P < 0.01) while promoting total VFA concentration (P < 0.01). Tributyrin improved the structure of rumen bacteria by enhancing Clostridium (P = 0.04), Butyrivibrio (P < 0.01), Streptococcus (P = 0.04), Prevotella (P = 0.04), Ruminobacter (P = 0.02) and Fibrobacter (P = 0.03). In conclusion, tributyrin could stimulate gastrointestinal tract development by enhancing colonization of rumen VFA-producing bacteria, and dietary supplementation of tributyrin at 4.0g/kg of DM was recommended for the weaned lambs.

The microbiota of the gastrointestinal tract influences gut health, which in turn strongly impacts the general health and productivity of laying hens. It is essential to characterise the composition and temporal development of the gut microbiota in healthy layers raised under different management systems, to understand the variations in typical healthy microbiota structure, so that deviations from this might be recognised and correlated with production and health issues when they arise. The present investigation aimed to study the temporal development and phylogenetic composition of the gut microbiota of four commercially raised layer flocks from hatch to end of the production cycle. Non-intrusive faecal sampling was undertaken as a proxy to represent the gut microbiota. Sequencing of 16S rRNA gene amplicons was used to characterise the microbiota. Beta diversity analysis indicated that each faecal microbiota was different across the four flocks and had subtly different temporal development patterns. Despite these inter-flock differences, common patterns of microbiota development were identified. Firmicutes and Proteobacteria were dominant at an early age in all flocks. The microbiota developed gradually during the rearing phase; richness and diversity increased after 42 d of age and then underwent significant changes in composition after the shift to the production farms, with Bacteroidota becoming more dominant in older birds. By developing a more profound knowledge of normal microbiota development in layers, opportunities to harness the microbiota to aid in the management of layer gut health and productivity may be more clearly seen and realised.

Developing effective strategies to prevent diarrhea and associated-gut disorders in mammals has gained great significance. Owing to the many health benefits provided by the commensal microbiota of the intestinal tract, such as against environmental perturbation, we explored the host phenotype-associated microbes and their probiotic potential. Based on the observations that the chronic heat stress-exposed weaned piglets present as heat stress-susceptible (HS-SUS) or heat stress-resistant (HS-RES) individuals, we confirmed the phenotypic difference between the two on growth performance (P < 0.05), diarrhea index (P < 0.001), intestinal heat shock protein 70 (HSP70) regulation (P < 0.01), and inflammatory responses (P < 0.01). By comparing the gut microbiome using 16S rRNA gene sequencing and KEGG functional analysis, we found that Lactobacillus johnsonii exhibited significantly higher relative abundance in the HS-RES piglets than in the HS-SUS ones (P < 0.05). Further experiments using a mouse model for chemical-induced inflammation and intestinal injury demonstrated that oral administration of a representative L. johnsonii N5 (isolated from the HS-RES piglets) ameliorated the clinical and histological signs of colitis while suppressing intestinal pro-inflammatory cytokines TNF-α and IL-6 production (P < 0.05). We found that N5 treatment enhanced tight junction proteins ZO-1 and occludin and cytoprotective HSP70 levels under physiological condition and restored their mucosal expressions in colitis (P < 0.05). In support of the high production of the anti-inflammatory cytokine IL-10, N5 promoted the intestinal Peyer's patches MHCII⁺ and CD103⁺ dendritic cell populations (P < 0.05), increased the regulatory T (Treg) cell numbers (P < 0.05), and decreased the Th17 population and its IL-17a production under physiological condition and during colitis (P < 0.01). Our results shed light on understanding the interaction between commensal Lactobacillus and the host health, and provide L. johnsonii N5 as an alternative to antibiotics for preventing diarrhea and intestinal diseases.

Sustained dysfunction of the intestinal barrier caused by early weaning is a major factor that induces postweaning diarrhea in weaned piglets. In both healthy and diseased states, the intestinal barrier is regulated by goblet cells. Alterations in the characteristics of goblet cells are linked to intestinal barrier dysfunction and inflammatory conditions during pathogenic infections. In this review, we summarize the current understanding of the mechanisms of the unfolded protein response (UPR) and anterior gradient 2 (AGR2) in maintaining intestinal barrier function and how modifications to these systems affect mucus barrier characteristics and goblet cell dysregulation. We highlight a novel mechanism underlying the UPR-AGR2 pathway, which affects goblet cell differentiation and maturation and the synthesis and secretion of mucin by regulating epidermal growth factor receptor and mucin 2. This study provides a theoretical basis and new insights into the regulation of intestinal health in weaned piglets.

This study was to compare the estimates of basal endogenous losses (BEL) of amino acids (AA) determined by 3 methods including feeding a nitrogen-free diet (NFD) or a low-casein diet (LCD, containing casein at 30g/kg diet) or using the regression method. Another objective was to investigate whether the ileal AA digestibility of corn calculated from a casein-supplemented corn diet is additive for a corn-soybean meal (SBM) mixed diet in broilers. On d 31 of age, 168 Ross 308 male broilers were assigned to 8 dietary treatments with 6 replicates in a randomized complete block design. An NFD and 3 diets containing 30, 60, or 90g/kg of casein were formulated to determine the BEL of AA and ileal AA digestibility of casein. The other 4 diets consisted of a corn diet, SBM diet, casein-supplemented corn diet, and corn-SBM mixed diet. On d 35 of age, digesta from the distal section of the ileum were collected. The BEL of AA in birds fed the LCD were greater (P < 0.05) than those of the NFD and the regression method. There were no differences in the BEL of AA determined between the NFD and the regression method. Apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA for corn calculated from the casein-supplemented corn diet were greater (P < 0.05) than those of the corn diet. The predicted AID of Thr in the corn-SBM mixed diet based on the AID of AA for corn in the corn diet was lower (P < 0.05) than the measured AID. However, the predicted AID of AA in the mixed diet based on the AID of AA for corn in the casein-supplemented corn diet did not differ from the measured AID. The predicted SID of AA in the mixed diet did not differ from the measured SID irrespective of casein supplementation. In conclusion, feeding an NFD or using the regression method yields similar BEL of AA, but not feeding an LCD. Casein supplementation in the corn diet increases the ileal AA digestibility for corn, which is additive for the corn-SBM mixed diet.

Given the key role of methionine in biological processes, adequate methionine should be provided to meet the nutritional requirements. DL-2-hydroxy-4-(methylthio)-butanoic acid (DL-HMTBA) has been considered as an important source of methionine. However, the effects of different sources and levels of methionine on the intestinal health status have not been clarified yet. An experiment was carried out to investigate the effects of different dietary sources and levels of methionine on the intestinal epithelial barrier, inflammatory cytokines expression, ileal morphology, microbiota composition, and cecal short chain fatty acids (SCFA) profiles. For this purpose, 720 male Arbor Acre broiler chicks at 1d old were randomly assigned to a 2 × 3 factorial arrangement with 2 methionine sources (DL-methionine and DL-HMTBA) and 3 total sulfur amino acids (TSAA) levels (80%, 100%, and 120% of Arbor Acre recommendation). The results showed that DL-HMTBA supplementation promoted intestinal physical barrier at both gene expression level of claudin-1 and serum diamine oxidase level (P < 0.05), and the inflammatory cytokine IL-6 mRNA expression was down-regulated by dietary DL-HMTBA supplementation compared with the DL-methionine group (P < 0.05). Meanwhile, an upregulated gene expression of claudin-1 and zonula occluden-1 (ZO-1) were observed in the low-TSAA treatment on d 14 (P < 0.05), whereas this treatment increased the expression of IL-1β and IL-6 (P < 0.05). Villus height to crypt depth ratio was high (P < 0.05) in the middle-level TSAA group. Furthermore, DL-HMTBA supplementation optimized the microbiota of the ileum especially the relative abundance of Lactobacillus, where the digestion and absorption were completed, and elevated the concentrations of SCFA (acetate, propionate, and butyrate) in the cecal content on d 21 (P < 0.01). In conclusion, dietary DL-HMTBA supplementation improved the intestinal barrier function, immune homeostasis and optimized the microbiota to promote intestinal health status in broiler chickens.

Mycotoxins are toxic compounds that pose a serious threat to animal health and food safety. Therefore, there is an urgent need for safe and efficient methods of detoxifying mycotoxins. As biotechnology has continued to develop, methods involving biological enzymes have shown great promise. Biological enzymatic methods, which can fundamentally destroy the structures of mycotoxins and produce degradation products whose toxicity is greatly reduced, are generally more specific, efficient, and environmentally friendly. Mycotoxin-degrading enzymes can thus facilitate the safe and effective detoxification of mycotoxins which gives them a huge advantage over other methods. This article summarizes the newly discovered degrading enzymes that can degrade four common mycotoxins (aflatoxins, zearalenone, deoxynivalenol, and ochratoxin A) in the past five years, and reveals the degradation mechanism of degrading enzymes on four mycotoxins, as well as their positive effects on animal production. This review will provide a theoretical basis for the safe treatment of mycotoxins by using biological enzyme technology.

Post-weaning diarrhea (PWD) in piglets poses a significant challenge and presents a grave threat to the global swine industry, resulting in considerable financial losses and compromising the welfare of animals. PWD is commonly associated with gut homeostatic imbalance, including oxidative stress, excessive inflammation, and microbiota dysbiosis. Antibiotic use has historically been a common initiative to combat PWD, but concerns about the development of antibiotic resistance have led to increased interest in alternative strategies. Mitochondria are key players in maintaining cellular homeostasis, and their dysfunction is intricately linked to the onset and progression of PWD. Accumulating evidence suggests that targeting mitochondrial function using antioxidant nutrients, such as vitamins, minerals and polyphenolic compounds, may represent a promising approach for preventing and treating PWD. Moreover, nutrients based on antioxidant strategies have been shown to improve mitochondrial function, restore intestinal redox balance, and reduce oxidative damage, which is a key driver of PWD. The present review begins with an overview of the potential interplay between mitochondria and gut homeostasis in the pathogenesis of PWD in piglets. Subsequently, alternative strategies to prevent and treat PWD using antioxidant nutrients to target mitochondria are described and discussed. Ultimately, we delve into potential limitations and suggest future research directions in this field for further advancement. Overall, targeting mitochondria using antioxidant nutrients may be a promising approach to combat PWD and provides a potential nutrition intervention strategy for regulating gut homeostasis of weaned piglets.

Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance. The objective was to evaluate the effects of diet medication (antibiotics) and β-glucanase (BGase) on digesta soluble β-glucan depolymerization, carbohydrate fermentation, and performance of coccidiosis-vaccinated broiler chickens fed wheat-based diets. A total of 1,782 broilers were raised on litter floor pens, and each treatment was assigned to 1 pen in each of the 9 rooms. The 3 dietary treatments were based on wheat as the sole grain (control, control + medication and control + 0.1% BGase), and the birds were fed the respective treatments ad libitum from 0 to 33d. Treatments were arranged in a randomized complete block design and analyzed as a one-way ANOVA. Beta-glucanase reduced the peak molecular weight, weight average molecular weight (Mw) and maximum molecular weight for the smallest 10% β-glucan molecules (MW-10%) in ileal digesta at d 11 and 33, whereas diet medication reduced Mw and MW-10% at d 33 compared to the control (P < 0.01). Beta-glucanase and medication reduced the ileal viscosity at d 11 compared to the control (P = 0.010). Ileal propionic acid concentration at d 11 and caecal total SCFA, acetic, and butyric acid concentrations at d 33 were lower in the BGase-supplemented diet than in the control (P < 0.05). The BGase-added diet had higher duodenal pH compared to the control at d 33 (P = 0.026). The effect of medication on carbohydrate fermentation was minimal. Diet medication increased weight gain after d 11, whereas BGase increased the gain for the total trial period compared to the control (P < 0.001). Feed intake was not affected by the dietary treatment. Medication and BGase improved feed efficiency after d 11 compared to the control (P < 0.001). The response to diet medication was larger than BGase, considering weight gain and feed efficiency after d 11 (P < 0.001). In conclusion, diet medication and BGase depolymerized high molecular weight ileal soluble β-glucan and increased overall bird performance. Dietary BGase may benefit bird health in broilers fed wheat-based diets without medication.

Medium-chain fatty acids and their derivatives are natural ingredients that support immunological functions in animals. The effects of glycerol monolaurate (GML) on intestinal innate immunity and associated molecular mechanisms were investigated using a chicken embryo model. Sixty-four Arbor Acres broiler embryos were randomly allocated into four groups. On embryonic day 17.5, the broiler embryos were administered with 9mg of GML, which was followed by a 12-h incubation period and a 12-h challenge with 32μg of lipopolysaccharide (LPS). On embryonic day 18.5, the jejunum and ileum were harvested. Results indicated that GML reversed the LPS-induced decline in villus height and upregulated the expression of mucin 2 (P < 0.05). GML decreased LPS-induced malondialdehyde production and boosted antioxidant enzyme activity (P < 0.05). GML alleviated LPS-stimulated intestinal secretion of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) (P < 0.05). GML also normalized LPS-induced changes in the gene expression of Toll-like receptor 4, nuclear factor kappa-B p65 (NF-κB p65), cyclooxygenase-2, NOD-like receptor protein 3, IL-18, zonula occludens 1, and occludin (P < 0.05). GML enhanced as well the expression of AMP-activated protein kinase α1 and claudin 1 (P < 0.05). In conclusion, GML improved intestinal morphology and antioxidant status by alleviating inflammatory responses and modulating NF-κB signaling in LPS-challenged broiler embryos.

The leaves of Eucommia ulmoides are rich in bioactive constituents that have potential gastrointestinal benefits for animals. In aged laying hens, intestinal health issues contribute to a significant decline in egg-laying capacity during intermediate and later stages. It remains unclear whether E. ulmoides leaf extract (ELE) can improve intestinal health and enhance egg production in elderly laying hens, and the underlying mechanisms are yet to be elucidated. Therefore, we conducted a study with 480 laying hens (65 weeks old) randomly allocated into four groups: a control group fed with the basal diet, and three treatment groups supplemented with 500, 1,000, and 2,000mg/kg of ELE, respectively. The primary active constituents of ELE include flavonoids, polysaccharides, terpenoids, and phenolic acids. Dietary supplementation with ELE at 1,000mg/kg (ELE1000) significantly improved laying performance and egg quality compared to the other groups. ELE1000 stimulated the maturation of intestinal epithelial cells, increased villus height, and reduced crypt depth. It also influenced the levels of proteins associated with tight junctions (claudin-1 and claudin-2) and intestinal inflammatory factors (IL-6, IL-1β, and IL-2) in different intestinal sections. Integrative analysis of serum metabolomics and gut microbiota revealed that ELE1000 improved nutrient metabolism by modulating amino acid and ubiquinone biosynthesis and influenced the abundance of intestinal microbiota by enriching pivotal genera such as Bacteroides and Rikenellaceae_RC9_gut_group. We identified 15 metabolites significantly correlated with both gut microbiota and laying performance, e.g., DL-methionine sulfoxide, THJ2201 N-valerate metabolite, tetracarbonic acid, etc. In conclusion, ELE1000 improved laying performance in elderly laying hens by affecting intestinal morphology, barrier function, microbiota, and serum metabolite profiles. These findings suggest that ELE can be a beneficial feed additive for extending the peak producing period in aged laying hens.

This study was conducted to evaluate the effects of dietary crude protein (CP) and rumen-protected lysine (RPL) supplementation on lactation performance, amino acid (AA) balance, nitrogen (N) utilization and hindgut microbiota in dairy cows. Treatments were in a 2 × 2 factorial arrangement, and the main effects were CP concentration (16% vs. 18%) and RPL supplementation (with or without RPL at 40 g/cow per day). Forty cows were randomly allocated to 4 groups: low-CP diet (LP), low-CP diet plus RPL (LPL), high-CP diet (HP), high-CP diet plus RPL (HPL). The experiment was conducted for 8 weeks. Results showed that RPL increased the dry matter intake (P < 0.01), milk protein yield (P = 0.04) and energy corrected milk (P = 0.04), and tended to increase milk fat yield (P = 0.06) and fat corrected milk (P = 0.05). Cows in the HP group tended to have higher milk urea N (P = 0.07). Plasma concentrations of Arg, Ile, Lys, Met, Pro, total essential AA and total nonessential AA were increased by RPL (P < 0.05). The total essential AA, total nonessential AA and most AA (except Ile, Phe, Gly and Pro) were increased in the HP group (P < 0.05). N excretion was increased in the HP group through an increase in urea N excretion (P < 0.01) and an upward trend in plasma urea N (P = 0.07). In addition, RPL tended to increase milk protein N secretion (P = 0.08), milk N (P = 0.07) and microbial protein synthesis (P = 0.06), and decreased plasma urea N (P < 0.001). In the hindgut, the bacterial community were different between the LP and LPL groups (P < 0.01). The probiotic abundances of Christensenellaceae_R-7_group and Acinetobacter were increased by RPL (P = 0.03 and 0.03, respectively). The pathogenic abundances of Clostridium_sensu_stricto_1 (P < 0.001) and Turicibacter (P < 0.01) were decreased by RPL. In conclusion, supplementing RPL with low dietary CP could balance AA supply and increase milk protein yield, resulting in an improvement in N utilization efficiency, and altered the composition of the hindgut microbiota to favor the lactation performance of dairy cows.

This study aimed to investigate the feeding effect of wheat silage on growth performance, nutrient digestibility, rumen fermentation, and microbiota composition in feedlot lambs. Sixty-four male crossbred Chinese Han lambs (BW = 27.8 ± 0.67kg, 3 months of age) were randomly assigned to four ration groups with wheat silage replacing 0% (WS0), 36% (WS36), 64% (WS64), and 100% (WS100) of oaten hay on forage dry matter basis. The concentrate-to-forage ratio was 80:20 and the feeding trial lasted 52 d. Increasing wheat silage inclusion linearly decreased dry matter intake by 4% to 27% (P < 0.01). However, increasing the wheat silage replacement of oaten hay by no more than 64% improved the feed efficiency by 14% as noted by the feed-to-gain ratio (P = 0.04). Apparent digestibility of organic matter (P < 0.01), neutral detergent fibre (P = 0.04) and acid detergent fibre (P < 0.01) quadratically increased. Ammonia nitrogen (P = 0.01) decreased while microbial protein production (P < 0.01) increased with the increase of wheat silage inclusion. Total volatile fatty acids concentration increased quadratically with the increase of wheat silage inclusion (P < 0.01), and the highest occurred in WS64. The molar proportion of acetate (P < 0.01) and acetate-to-propionate ratio (P = 0.04) decreased while butyrate (P < 0.01) and isovalerate (P = 0.04) increased. Increasing wheat silage inclusion increased the Firmicutes-to-Bacteroidota ratio by 226% to 357%, resulting in Firmicutes instead of Bacteroidota being the most abundant phylum. The relative abundance of cellulolytic Ruminococcus numerically increased but that of amylolytic Prevotella (P < 0.01) decreased as increasing wheat silage inclusion. Taken together, increasing wheat silage replacement of oaten hay by no more than 64% exhibited greater feed efficiency and fibre digestion despite low feed intake by feedlot lambs due to the change of Firmicutes-to-Bacteroidota ratio in the rumen.

Rosemary extracts have been widely used as feed additives in recent years. This study aimed to investigate the effects of rosmarinic acid (RA) and ursolic acid (UA), the main active components of rosemary, on growth performance, meat quality and lipid metabolism in finishing pigs. A total of 72 finishing pigs (Landrace; initial age of 150 d) were randomly divided into 3 treatments with 8 replicates of 3 pigs each, and fed a basal diet or diet containing 500mg/kg of RA or UA. The results showed that dietary supplementation of RA or UA had no significant effect on the growth performance and carcass traits of finishing pigs (P > 0.05). However, both RA and UA significantly increased the triglyceride (TG) level in soleus muscle (P < 0.001). Supplementation of RA increased the expression of genes related to lipogenesis and transport including fatty acid synthase (FAS) (P < 0.001), sterol regulatory element binding protein-1c (SREBP1c) (P < 0.001) and peroxisome proliferator-activated receptor γ (PPARγ) (P < 0.05), while UA increased the expression of fatty acid transport protein 1 (FATP1), a gene related to lipid uptake (P < 0.05). However, RA reduced the expression of adipogenesis-related gene acetyl-coenzyme A carboxylase α (ACCα) (P < 0.01). Characterization of cecal microbiota indicated that RA increased the microbial richness (chao 1, P < 0.001) and diversity (observed species, P < 0.01). Further analysis of the genera revealed that RA increased the relative abundance of Bacteroides and g-UCG-005 (P < 0.05), and UA enriched Prevotella (P < 0.001). Correlation analysis showed that g-UCG-005 was positively correlated with the expression of FAS, carnitine palmitoyl transferase 1B (CPT1B), SREBP1c and PPARγ (P < 0.01). In conclusion, dietary supplementation of RA or UA may increase fat deposition in muscle of finishing pigs by regulating lipid metabolism and gut microbiota.

Tocopherol sources in diets are often a combination of all-rac-α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4′R, 8′R)-5,7,8-trimethyltocotrienol (α-tocotrienols) from the feed sources. Synthetic α-tocopherol consists of 8 different stereoisomers including 2R-(4′R, 8′R)-5,7,8-trimethyltocol (RRR-α-tocopherol), 2R-(4′S, 8′R)-5,7,8-trimethyltocol (RSR-α-tocopherol), 2R-(4′R, 8′S)-5,7,8-trimethyltocol (RRS-α-tocopherol), 2R-(4′S, 8′S)-5,7,8-trimethyltocol (RSS-α-tocopherol), 2S-(4′S, 8′S)-5,7,8-trimethyltocol (SSS-α-tocopherol), 2S-(4′R, 8′S)-5,7,8-trimethyltocol (SRS-α-tocopherol), 2S-(4′S, 8′R)-5,7,8-trimethyltocol (SSR-α-tocopherol), and 2S-(4′R, 8′R)-5,7,8-trimethyltocol (SRR-α-tocopherol). The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen. The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract (synthesis, digestion), and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4 × 4 Latin square design for 4 periods. Cows were fed a total mixed ration ad libitum containing different forms of oats: whole oat, decorticated oat, toasted oat, and decorticated toasted oat, all rolled before mixed ration. Overall means across 4 treatments were statistically analyzed, testing whether overall means were different from zero. Decortication or toasting did not affect the balance or digestibility of α-tocopherols in rumen. Average across treatments showed the ruminal degradation of synthetic α-tocopherol (279 mg/d, P = 0.02; P-value shows that average across treatments is different from zero), synthetic 2R-α-tocopherol (133 mg/d, P < 0.01; summation of RRS-, RSR- and RSS-α-tocopherol), and 2S-α-tocopherol (190 mg/d; P < 0.01, summation of SSS-, SRS-, SSR, and SRR-α-tocopherol), while RRR-α-tocopherol was formed in the rumen (221 mg/d, P = 0.10). The average across treatments showed that small intestinal digestibility of tocopherols ranked in the following order: α-tocotrienol > natural α-tocopherol > synthetic atocopherols > 2R-(4'R, 8'R)-,7,8-dimethyltocol (γ-tocopherol). The average across treatments for small intestinal and feed-ileum digestibility ranked in the following order: RRR-a-tocopherol > synthetic 2R-α-tocopherol > 2S-α-tocopherol. Results showed the first evidence for RRR-α-tocopherol formation under anaerobic conditions in the rumen. In addition, synthetic γ-tocopherol stereoisomers, g-tocopherol and a-tocotrienol were degraded in the rumen. There was a discrimination against absorption of synthetic 2R- and 2S-α-tocopherol in the small intestine.

Tryptophan (Trp) is an essential amino acid that cannot be synthesized by animals. It has been characterized into two different isomers, levorotation-Trp (L-Trp) and dextrorotation-Trp (D-Trp), based on their distinct molecule orientation. Intestinal epithelial cells and gut microbiota are involved in metabolizing L-Trp in the gut via the activation of the kynurenine, serotonin, and indole pathways. However, knowledge regarding D-Trp metabolism in the gut remains unclear. In this review, we briefly update the current understanding of intestinal L/D-Trp metabolism and the function of their metabolites in modulating the gut physiology and diseases. Finally, we summarize the effects of Trp nutrition on swine production at different stages, including growth performance in weaned piglets and growing pigs, as well as the reproduction performance in sows.

Aquatic animals have benefited from Bacillus subtilis-based probiotics over the past few decades. This study evaluated the effects of B. subtilis DSM 32315 probiotics as a feed additive on growth, immune response and resistance to acute ammonia challenge in Nile tilapia. Specifically, four supplemental levels (0%, 0.1%, 0.2%, and 0.3%) of B. subtilis probiotics were tested under two dietary protein levels (32% and 28%). Five replicate tanks were randomly allotted to each dietary treatment, with each tank containing 30 Nile tilapia. After 8 weeks of feeding, Nile tilapia in each tank were exposed to 43.61 mg/L of total ammonia nitrogen for 48 h. The results revealed that reducing protein levels from 32% to 28% did not affect growth performance or antioxidant capacity. However, the low protein diet tended to induce an inflammatory effect shown by increased expressions of TGF-β and IFN-γ genes (P < 0.05) in the liver. The impact was alleviated by the probiotic supplementation. Compared with the non-supplemented group, 0.1% probiotic supplementation remarkably increased plasma lysozyme activity, total antioxidant capacity and complement C3 and interleukin-10 mRNA levels (P < 0.05) in the 28% protein diet, while higher supplementation of probiotics (0.3%) was shown to be beneficial for the high protein diet (32%). In both the dietary protein levels, 0.1% supplementation of probiotics promoted the antioxidant capacity of Nile tilapia before exposure to ammonia stress but higher probiotic supplementation (0.3%) proved to be necessary under ammonia stress as evidenced by higher fish survival rate. Results exhibited that supplementation with B. subtilis probiotics had a better effect on the intestinal morphology (villi height and width) regardless of protein levels. In conclusion, dietary supplementation of B. subtilis DSM 32315 probiotics at 0.1% in the low protein diet and up to 0.3% in the high protein diet showed beneficial effects on the growth, immunity, and antioxidant capacity of Nile tilapia. Under ammonia stress conditions, the higher supplementation of B. subtilis DSM 32315 probiotics at 0.3% improves stress tolerance of Nile tilapia despite the two dietary protein levels (32%; 28%).

Piglets are particularly susceptible to oxidative stress, which causes inferior growth performance and intestinal damage. Squalene (SQ), a natural bioactive substance enriched in shark liver oil, shows excellent antioxidant properties and can currently be obtained at a low cost from deodorizer distillate during the production of plant oil. This study aimed to evaluate the effects of plant-derived SQ supplementation on the growth performance of piglets and explore the beneficial roles of SQ against oxidative stress and intestinal injury in diquat-challenged piglets. Forty piglets were randomly divided into five groups and fed a basal diet supplemented with SQ at 0, 500, 1000, or 2000mg/kg for 5 weeks. Acute oxidative stress was induced in the piglets with diquat (10mg/kg BW) at the fourth week of the experiment, followed by a 7-d recovery period. Results showed that before the diquat challenge, SQ supplementation significantly improved growth performance (average daily gain and feed conversion ratio) and serum antioxidant status, and after the diquat challenge, SQ supplementation significantly mitigated diquat-induced growth arrest, intestinal villous atrophy, intestinal epithelial cell apoptosis, intestinal hyperpermeability, and deficiency of intestinal epithelial tight junction proteins (zonula occludens-1, occludin, and claudin-3). Under oxidative stress induced by diquat, SQ supplementation consistently improved the antioxidant status of the small intestine, liver, and muscle. In vitro, SQ was shown to alleviate hydrogen peroxide (H₂O₂)-induced increase of the levels of intracellular reactive oxygen species and apoptosis of porcine intestinal epithelial cells. Taken together, SQ supplementation improves growth performance and effectively alleviates acute oxidative stress-induced growth retardation and intestinal injury via improving antioxidant capacity in piglets. Our findings may provide an efficient strategy for alleviating oxidative stress-induced inferior growth performance and intestinal damage in piglets.

The primary objective of this study was to investigate the influence of high and low inclusions of nonbound amino acid (NBAA) in standard and reduced-crude protein (CP), wheat-based diets on growth performance in broiler chickens. Dietary treatments were formulated to either 210 or 180g/kg CP. The 210g/kg CP diets contained either 12.1 or 21.1g/kg NBAA and 180g/kg CP diets contained either 44.0 or 55.5g/kg NBAA. The formulations also generated different dietary starch:protein ratios which impacted on starch-protein digestive dynamics. Each of the four dietary treatments were offered to 7 replicates of 15 birds housed in floor pens from 14 to 35 days post-hatch or a total of 420 male Ross 308 chickens. Growth performance, relative abdominal fat-pad weights, breast muscle and leg shank yields were determined. Ileal starch and protein (N) digestibility coefficients, disappearance rates and starch:protein disappearance rate ratios were defined. Apparent ileal digestibility coefficients and disappearance rates of 16 amino acids were determined at 35 days post-hatch and free concentrations of 20 amino acids in systemic plasma were determined at 34 days post-hatch. The transition from 210 to 180g/kg CP diets depressed weight gain by 11.3% (1742 versus 1964g/bird) and FCR by 10.4% (1.606 versus 1.455), although both parameters were subject to treatment interactions. The treatment interaction (P < 0.001) observed for FCR was because high NBAA inclusions significantly improved FCR by 4.17% (1.424 versus 1.486) in birds offered 210g/kg CP diets, but significantly depressed FCR by 3.36% (1.632 versus 1.579) in 180g/kg CP diets. A quadratic relationship (r = 0.860; P < 0.001) between dietary NBAA inclusions and FCR was detected, which indicated that when NBAA inclusions exceed 18.5g/kg efficiency of feed conversion deteriorated. However, a multiple linear regression (r = 0.913; P < 0.001) was detected for FCR where both NBAA inclusions and analysed dietary starch:protein ratios were significantly (P < 0.001) related to FCR. This relationship indicates that growth performance of broiler chickens offered wheatbased diets is strongly influenced by dietary NBAA inclusions coupled with dietary starch:protein ratios and consideration is given to the possible underlying mechanisms.

Hindered growth often occurs because of psychological and environmental stress during the weaning period of piglets. This study aimed to compare the effects of growth performance, diarrhea indices, digestibility of nutrients, antioxidant capacity, neurotransmitters levels and metabolism of weaned pigs fed diets supplemented with pyrroloquinoline quinone (PQQ) and zinc oxide (ZnO). Pigs weaned at d 28 (n = 108) were fed with three different diets including: the basal diet (CTRL group), the basal diet supplemented with 3.0mg/kg PQQ (PQQ group) and the basal diet containing 1,600mg/kg ZnO (ZNO group). During the first 14 d, weaned pigs fed the diet supplemented with PQQ and ZnO decreased feed to gain ratio and diarrhea rate (P < 0.01). Compared with the CTRL group, average daily gain was increased in weaned pigs in the PQQ group from d 15 to 28 (P = 0.03). Compared with the CTRL group, pigs fed PQQ and ZnO supplemented diets showed improved apparent total tract digestibility (ATTD) of nutrients (P ≤ 0.05). During the overall experimental period, the concentration of malondialdehyde was decreased in plasma of pigs in the PQQ and ZNO groups compared with the CTRL group (P < 0.05). At d 28, the concentration of vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) was lower in plasma of weaned pigs in the PQQ and ZNO groups compared with the CTRL group (P < 0.05). There was no difference between the PQQ and ZNO group in growth performance, ATTD of nutrition, antioxidant capacity and neurotransmitters levels. PQQ increased 3-methoxy-4-hydroxymandelate (P < 0.05) compared with the CTRL group. According to metabolomic analysis, erucamide, formononetin and 3-methyl-L-histidine were up-regulated in the PQQ group (P < 0.05). Compared with the CTRL group, aloesin and dibutyl adipate were down-regulated in the PQQ group (P < 0.05). In conclusion, similar to ZnO, PQQ improves growth performance, digestibility of nutrients, antioxidant capacity, neuromodulation and metabolism of weaned pigs. Thus, like ZnO, PQQ can be effectively applied in weaned pigs.

To explore the effects of fermented rapeseed meal (FRSM) on growth performance and intestinal health, a total of 30 growing pigs were randomly allotted to three treatments consisting of corn-soybean meal diet (CSD), rapeseed meal diet (RSD), and fermented rapeseed meal diet (FRSD). Results showed that compared with RSD, FRSD feeding increased the average daily gain and final body weight in pigs (P < 0.01). Compared with RSD feeding, FRSD feeding elevated the apparent digestibility of crude protein, acid detergent fiber, and ether extract in pigs (P < 0.01). Moreover, the FRSD group exhibited greater apparent ileal digestibility of His, Thr, Lys, and Ser than the RSD group (P < 0.01). The digestible energy, metabolic energy, and nitrogen utilization were higher in the FRSD and CSD groups than in the RSD group (P < 0.01). As compared to the RSD, FRSD feeding decreased the serum concentration of leptin but significantly increased the concentrations of immunoglobulin (Ig) A, IgG, ghrelin, and enzyme activities of amylase, lipase, and trypsin in the pancreas (P < 0.05). Interestingly, the villus height, the ratio of villus height to crypt depth, and the activities of brush border enzymes (e.g., maltase and sucrase) in the small intestine were higher in the CSD and FRSD groups than in the RSD group (P < 0.05). As compared to the RSD, the FRSD feeding not only increased the expression level of the occludin in the small intestinal epithelium (P < 0.05) but also elevated the expression levels of claudin-1, MUC1, and PepT1 genes in the duodenum, and elevated the expression levels of SGLT1 and CAT1 genes in the jejunum (P < 0.05). Importantly, FRSD feeding significantly decreased the abundance of Escherichia coli, but increased the abundance of Lactobacillus and the content of butyrate in the cecum and colon (P < 0.05). These results indicated that compared with rapeseed meal, fermented rapeseed meal exhibited a positive effect on improving the growth performance and intestinal health in growing pigs, and the results may also help develop novel protein sources for animal nutrition and the feed industry.

A 21-d experiment was conducted to study the effect of xylanase, protease, and xylo-oligosaccharides on growth performance, nutrient utilization, gene expression of nutrient transporters, cecal short-chain fatty acids (SCFA), and cecal microbiota profile of broilers challenged with mixed Eimeria spp. The study utilized 392 zero-d-old male broiler chicks allocated to 8 treatments in a 4 × 2 factorial arrangement, as follows: corn-soybean meal diet with no enzyme (Con); Con plus xylanase alone (XYL); Con plus xylanase combined with protease (XYL + PRO); or Con plus xylo-oligosaccharides (XOS); with or without Eimeria challenge. Diets were based on a high-fiber (100g/kg soluble fibers and 14g/kg insoluble fibers) basal diet. At d 15, birds in challenged treatment were gavaged with a solution containing Eimeria maxima, Eimeria acervulina, and Eimeria tenella oocysts. At d 21, birds were sampled. Eimeria depressed (P < 0.01) growth performance and nutrient utilization, whereas supplementation had no effect. There were significant Eimeria × supplementation interactions for the sugar transporters GLUT5 (P = 0.02), SGLT1 (P = 0.01), SGLT4 (P < 0.01), and peptide transporter PepT1 (P < 0.01) in jejunal mucosa. Eimeria challenge increased the expression of GM-CSF2 (P < 0.01) and IL-17 (P = 0.04) but decreased (P = 0.03) IL-1β expression in the cecal tonsil. Eimeria × supplementation interactions for cecal acetate, butyrate, and total SCFA showed that concentrations increased or tended to be greater in the supplemented treatments, but only in non-challenged birds. Birds challenged with Eimeria spp. had higher concentrations of isobutyrate (P < 0.01), isovalerate (P < 0.01), and valerate (P = 0.02) in cecal content. Eimeria challenge significantly (P < 0.01) decreased the microbial richness and diversity, and increased (P < 0.01) the proportion of Anaerostipes butyraticus, Bifidobacterium pseudolongum, and Lactobacillus pontis. In conclusion, Eimeria infection depressed growth performance, nutrient utilization with regulating nutrient transporters. Furthermore, Eimeria challenge shifted the microbial profile and reduced microbial richness and diversity. On the other hand, enzyme supplementation showed limited benefits, which included increased concentrations of SCFA.