Animal nutritionists have incessantly worked towards providing livestock with high-quality plant protein feed resources. Soybean meal (SBM) has been an essential and predominantly adopted vegetable protein source in livestock feeding for a long time; however, several SBM antinutrients could potentially impair the animal's performance and growth, limiting its use. Several processing methods have been employed to remove SBM antinutrients, including fermentation with fungal or bacterial microorganisms. According to the literature, fermentation, a traditional food processing method, could improve SBM's nutritional and functional properties, making it more suitable and beneficial to livestock. The current interest in health-promoting functional feed, which can enhance the growth of animals, improve their immune system, and promote physiological benefits more than conventional feed, coupled with the ban on the use of antimicrobial growth promoters, has caused a renewed interest in the use of fermented SBM (FSBM) in livestock diets. This review details the mechanism of SBM fermentation and its impacts on animal health and discusses the recent trend in the application and emerging advantages to livestock while shedding light on the research gap that needs to be critically addressed in future studies. FSBM appears to be a multifunctional high-quality plant protein source for animals. Besides removing soybean antinutrients, beneficial bioactive peptides and digestive enzymes are produced during fermentation, providing probiotics, antioxidants, and immunomodulatory effects. Critical aspects regarding FSBM feeding to animals remain uncharted, such as the duration of fermentation, the influence of feeding on digestive tissue development, choice of microbial strain, and possible environmental impact.

The production of selenium-enriched fish can contribute to alleviating selenium deficiency in human diets. However, it is still unclear which selenium source, as an additive, can efficiently and cost-effectively produce high-quality selenium-enriched fish. This study evaluated the effects of selenium nanoparticles (SeNP), selenite, and selenomethionine (SeMet) on the growth, antioxidant capacity, selenium content, selenium speciation, and meat quality of grass carp. Ten diets were prepared, including a basal diet (BD) and three concentrations (0.1, 0.3, and 0.9 mg/kg) of SeNP, selenite, and SeMet. A total of 600 fish (250.79 ± 1.57 g) were randomly assigned to 30 tanks (3 tanks/group). Fish were fed the experimental diet three times daily for 60 d. In this study, SeNP most significantly promoted the growth and antioxidant capacity of grass carp, with 0.3 mg/kg SeNP identified as the optimal additive concentration. Additionally, SeNP demonstrated equally excellent bioavailability as SeMet and significantly increased the content of SeMet in grass carp (Ctenopharyngodon idella) muscle. Furthermore, compared to SeMet and selenite, dietary SeNP could more significantly enhance the content of selenocysteine (SeCys₂) and methylselenocysteine (MeSeCys) in grass carp muscle tissue. In addition, we have demonstrated that SeCys₂ and MeSeCys promote apoptosis of cancer cells (HeLa) through the mitochondrial apoptotic pathway (involving Bax and Bcl-2). Furthermore, as an additive, 0.3 mg/kg SeNP significantly improved the flesh quality of grass carp by reducing crude fat and heavy metal content, as well as increasing the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the ratio of n-3/n-6 polyunsaturated fatty acid (PUFA). In summary, SeNP is the most suitable additive for producing selenium-enriched fish.

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.

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.

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.

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.

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%.

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.

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.