Ochratoxin A (OTA) is one of the most common pollutants in aquatic feed. As a first line of defense, intestinal barriers could be utilized against OTA in order to prevent disorders. Natural product supplementation is one of the most popular strategies to alleviate toxicity induced by mycotoxins, but there is a lack of knowledge about how it functions in the teleost intestine. In this study, 720 juvenile grass carp of about 11 g were selected and four treatment groups (control group, OTA group, curcumin [Cur] group, and OTA + Cur group) were set up to conduct a 60-day growth test. After the test, the growth performance and intestinal health related indexes of grass carp were investigated. The addition of dietary Cur could have the following main results: (1) inhibit absorption and promote efflux transporters mRNA expression, reducing the residuals of OTA, (2) decrease oxidative stress by reducing oxidative damage and enhancing the expression of antioxidant enzymes, (3) promote mitochondrial fusion proteins to inhibit the expression of mitotic proteins and mitochondrial autophagy proteins and enhance mitochondrial function, (4) reduce necroptosis-related gene expression through inhibiting the tumor necrotic factor receptor-interacting protein kinase/mixed lineage kinase domain-like pathway, (5) reduce the expression of pro-inflammatory factors by inhibiting the Toll-like receptor 4/nuclear factor-κB signaling pathway to alleviate the intestinal inflammatory response. In summary, the results suggested that Cur could alleviate OTA-induced intestinal damage by enhancing antioxidant capacity and mitochondrial function as well as reducing necroptosis and inflammation in the grass carp intestine. This study provided a theoretical basis and production implications for dietary Cur that could improve growth performance and alleviate the intestinal damage induced by OTA in fish.

Considerable research has been conducted into the efficacy of individual probiotics in broiler production, however information on the most effective combinations of synergistic Bacillus probiotic is lacking. This study investigated the impact of different Bacillus strain combinations in broiler chickens, as well as in vitro enzyme production. In experiment one, a total of 576 Ross 308 broilers at 1 d old were grown for 21 d across 6 treatments of maize-soybean diets (n = 12 pens per treatment) to compare three different strain combinations (formulation 1 [F1]: 3 strains Bacillus amyloliquefaciens; F2: Bacillus coagulans and 2 strains B. amyloliquefaciens; F3: B. coagulans, Bacillus licheniformis and 2 strains B. amyloliquefaciens; F5: Bacillus subtilis, B. licheniformis and 2 strains B. amyloliquefaciens), positive control (PC), and a negative control antibiotic treatment group (NC). In Exp. 2, a total of 360 one-day-old ROSS308 broilers were used to test five treatments (n = 9) including PC, NC, F1 and F5 (selected from Exp. 1), and F4 (Bacillus pumilis and 2 strains B. amyloliquefaciens) in a maize-soybean diet. B. amyloliquefaciens F1 demonstrated a significant improvement in feed conversion ratio (FCR) compared to F2 at d 14 (1.49 vs 2.10; P = 0.038) and the body weight (BW) at d 21 (847.0 g vs 787.4 g) compared to other combinations (P = 0.027). The FCR at d 21 tended to be lower in birds fed F1 (1.46 vs 1.66) compared to the control (P = 0.068). Probiotic treatments had significantly improved nutrient digestibility compared to the PC and NC. Also, probiotic treatments supported the growth of Streptococcus, a common commensal genus and reduced the abundance of genera that correlated with low weight gain such as Akkermansia. Experiment two revealed that F4 improved FCR (P < 0.001) and BW at 28 d (P = 0.014). In vitro testing showed a high production of protease and amylase by Bacillus. Thus, the addition of Bacillus probiotics, particularly containing B. amyloliquefaciens strains and Bacillus pumilus, into the diet of broiler chickens improves production performance, nutrient digestibility, and allows the proliferation of beneficial gut microbiota.

The intracellular lipids in muscle cells of farm animals play a crucial role in determining the overall intramuscular fat (IMF) content, which has a positive impact on meat quality. However, the mechanisms underlying the deposition of lipids in muscle cells of farm animals are not yet fully understood. The purpose of this study was to determine the roles of carbohydrate-response element binding protein (ChREBP) and fructose in IMF deposition of chickens. For virus-mediated ChREBP overexpression in tibialis anterior (TA) muscle of chickens, seven 5-d-old male yellow-feather chickens were used. At 10 d after virus injection, the chickens were slaughtered to obtain TA muscles for analysis. For fructose administration trial, sixty 9-wk-old male yellow-feather chickens were randomly divided into 2 groups, with 6 replicates per group and 5 chickens per replicate. The chickens were fed either a basal diet or a basal diet supplemented with 10% fructose (purity ≥ 99%). At 4 wk later, the chickens were slaughtered, and breast and thigh muscles were collected for analysis. The results showed that the skeletal ChREBP mRNA levels were positively associated with IMF content in multiple species, including the chickens, pigs, and mice (P < 0.05). ChREBP overexpression increased lipid accumulation in both muscle cells in vitro and the TA muscles of mice and chickens in vivo (P < 0.05), by activation of the de novo lipogenesis (DNL) pathway. Moreover, activation of ChREBP by dietary fructose administration also resulted in increased IMF content in mice and notably chickens (P < 0.05). Furthermore, the lipidomics analysis revealed that ChREBP activation altered the lipid composition of chicken IMF and tented to improve the flavor profile of the meat. In conclusion, this study found that ChREBP plays a pivotal role in mediating the deposition of fat in chicken muscles in response to fructose-rich diets, which provides a novel strategy for improving meat quality in the livestock industry.

Antinutritional factors in feedstuffs may limit their utilization in livestock production, but fermentation process can be used to improve feed quality; however, studies on fermented soybeans for laying hens remain limited. We investigated the effect of fermented soybean meal (FSBM) at various inclusion levels as a partial replacement for soybean meal (SBM) on egg production, egg quality, amino acid digestibility, gut morphology and microbiota, antioxidant capacity and immune response of young laying hens. A total of 360 Hy-line Brown laying hens aged 18 weeks were selected and divided into 5 groups of 6 replicates each and 12 birds per replicate. The control group received a basal diet while the trial group received the basal diet with FSBM included at 2.5%, 5.0%, 7.5% and 10.0%, respectively, for 12 weeks. Our findings revealed that the nutritional value of FSBM was higher compared to that of SBM in terms of reduced content of trypsin inhibitors and increased contents of crude protein, amino acids and minerals. FSBM enhanced egg production (P < 0.05), feed-to-egg ratio (P < 0.05), and albumen quality (albumen height and Haugh unit) (P < 0.05). Furthermore, FSBM improved apparent fecal amino acid digestibility (P < 0.05), gut morphology (increased villus height, villus width, villus height-to-crypt depth ratio and decreased crypt depth) (P < 0.05), antioxidant capacity (reduced malondialdehyde and increased catalase, total superoxide dismutase, glutathione peroxidase and total antioxidant capacity) (P < 0.05) and immune function (increased concentrations of IgG, IgA, and IgM; increased levels of transforming growth factor beta and Toll-like receptor 2; and reduced levels of interleukin 1β and tumor necrosis factor alpha) (P < 0.05). Further analysis showed that FSBM altered the composition of the gut microbiota favoring beneficial microbes. These findings suggest that probiotic fermentation improved the nutritional value of SBM. The inclusion of FSBM in the diets of laying hens at 2.5% or 5.0% improved amino acid digestibility, gut health, immune function, egg production and egg quality.

The study aimed to assess the effects of dietary black soldier fly oil (BSFO) on the growth performance, flesh quality, and health status of largemouth bass (Micropterus salmoides). Six iso-nitrogenous and isolipid diets were formulated by substituting fish oil and soybean oil (1/2, wt/wt) with BSFO in percentages of 0%, 20%, 40%, 60%, 80%, and 100%, respectively. The diets were fed to 960 fish (initial body weight = 16.5 g) in four replicates for 8 weeks. Indicators related to growth performance, body composition, hematology, flesh quality, expression of genes related to inflammatory cytokines and apoptosis, and the response of fish to Aeromonas veronii challenge were analyzed. The results showed that the weight gain rate was numerically improved in all BSFO substitution groups, ranging from 9.3% to 44.0% compared to the control group. The highest survival rate and the lowest hepatosomatic index and condition factor were observed in the BFSO20 group. In terms of flesh quality, the water-holding capacity of the dorsal muscle was elevated with higher levels of dietary BSFO. However, significant changes in texture properties (cohesiveness, gluing, and chewiness) were observed in the BSFO20 group (P < 0.05). Six hematological parameters related to glycolipid and liver function were optimized in most of the BFSO substitution groups. Furthermore, the expressions of six inflammation- and apoptosis-related genes (IL-1β, Bcl-xl, BAX, caspase8, TNF-α, and IL-10) were significantly affected by dietary BSFO (P < 0.05). Following bacterial challenge, the seven-day cumulative survival rates of fish were considerably increased from 10.0% in the control group to 60.0% and 66.7% in the BSFO80 and BSFO100 groups, respectively. One-variable linear regression analysis revealed that various parameters related to fish growth, flesh quality, and health status were significantly influenced by dietary BSFO substitution levels in a dose-dependent manner (P < 0.05). In conclusion, substituting around 20% of dietary fish oil and soybean oil with BSFO is promising in improving the growth performance and flesh quality of M. salmoides. However, to enhance immunity and disease resistance, it is recommended to further increase the inclusion of BSFO in the diet.

This review explores the potential of including glutamine, a so-called non-essential amino acid, in the formulation of reduced-crude protein (CP) diets for broiler chickens. There is a precedent for benefits when including glycine and serine in reduced-CP diets. Fundamentally this is due to decreases in non-essential amino acid concentrations in reduced-CP diets — an unavoidable consequence of reducing CP without amino acid supplementation. The situation for glutamine is complicated because analysed dietary concentrations are very rarely provided as standard assays do not differentiate between glutamine and glutamate and are reported on a combined basis as glutamic acid. The dietary requirement for glutamic acid is approximately 36.3 g/kg but it is increasingly unlikely that this requirement will be met as dietary CP levels are progressively reduced. Glutamine is an abundant and versatile amino acid and constitutes 50.5 mg/g of whole-body chicken protein and is the dominant free amino acid in systemic plasma where it has been shown to provide 22.6% (139.9 of 620.3 μg/mL) of the total in birds offered 215 g/kg CP, wheat-based diets. In addition to dietary intakes, glutamine biosynthesis is derived mainly from the condensation of glutamate and ammonia (NH₃) catalysed by glutamine synthetase, a reaction that is pivotal to NH₃ detoxification. Glutamate and NH₃ are converted to glutamine by phosphate-dependent glutaminase in the reciprocal reaction; thus, glutamine and glutamate are interchangeable amino acids. However, the rate of glutamine biosynthesis may not be adequate in rapidly growing broiler chickens and exogenous and endogenous glutamine levels are probably insufficient in birds offered reduced-CP diets. The many functional roles of glutamine, including NH₃ detoxification and maintenance of acid-base homeostasis, then become relevant. Twenty feeding studies were identified where dietary glutamine supplementation, usually 10 g/kg, was evaluated in birds kept under thermoneutral conditions. On balance, the outcomes were positive, but the average dietary CP was 213 g/kg across the twenty feeding studies, which indicates that CP and, in turn, glutamine concentrations would have been adequate. This suggests that glutamine inclusions in reduced-CP diets hold potential and consideration is given to how this may be best confirmed.

Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp (Litopenaeus vannamei) to utilize Chlorella sorokiniana (CHL), a 3 × 2 factorial design stocking experiment was used in this study. Specifically, shrimp was fed with two dietary protein sources (fishmeal [FM] and CHL) at low (LSD; 100 per m³), medium (MSD; 200 per m³) and high (HSD; 300 per m³) stocking densities for 8 weeks. The growth performance and resistance to Vibrio parahaemolyticus (1.0 × 10⁷ CFU/mL) of shrimp decreased with the increase of stocking density, but dietary CHL improved this result. Differences between the CHL and FM groups for V. parahaemolyticus resistance were significant only under high-density conditions (P < 0.05). Significant interactions between stocking density and protein source were found on the activities of catalase (CAT), superoxide dismutase (SOD) and phenol oxidase (PO), and the contents of malondialdehyde (MDA) in the hepatopancreas and the activities of intestinal amylase, most of which were significantly different between CHL and FM groups only at high stocking density (P < 0.05). Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota, inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria. Transcriptomic results showed that at high stocking densities, differentially expressed genes (DEGs) in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll, immune deficiency (Imd) and glycolysis–gluconeogenesis pathways. Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs, also more were detected under high density situations. In conclusion, CHL has great potential as a novel protein source in the intensive farming of shrimp.

The purpose of this study was to investigate the effects of dietary saccharin sodium supplementation on production performance, serum biochemical indicators, and rumen fermentation of dairy goats in summer. Twelve Guanzhong dairy goats with similar body weight, days in milk, and milk yield were randomly divided into two dietary treatments: (1) CON: basal diet; (2) SS: basal diet + 150 mg/kg saccharin sodium on the basis of dry matter. The experiment lasted 35 d, including 7 d for adaptation and 28 d for dietary treatments, sampling and data collection. Each dairy goat was housed individually in a clean separate pen with ad libitum access to diet and water. The goats fed SS diet had increased dry matter intake (DMI; P = 0.037), 4% fat corrected milk yield (P = 0.049), energy corrected milk yield (P = 0.037), milk protein yield (P = 0.031), and total solids yield (P = 0.036). Serum activity of aspartate aminotransferase (P = 0.047) and concentrations of 70-kDa heat shock protein (P = 0.090), malondialdehyde (P = 0.092), and total protein (P = 0.057) were lower in goats fed SS diet than those fed CON diet. Supplementation of saccharin sodium tended to increase activity of glutathione peroxidase in serum (P = 0.079). The concentrations of rumen total volatile fatty acid (P = 0.042) and butyrate (P = 0.038) were increased by saccharin sodium supplementation. Dietary supplementation of saccharin sodium increased the relative abundance of Lachnobacterium (P = 0.022), Pseudoramibacter (P = 0.022), Shuttleworthia (P = 0.025), and Syntrophococcus (P = 0.037), but reduced the relative abundance of Prevotella_1 (P = 0.037) and Lachnospiraceae_UCG_008 (P = 0.037) in rumen. Saccharin sodium was observed in feces and urine of goats fed diet supplemented with saccharin sodium, but saccharin sodium was undetectable in the milk of goats receiving SS diet. In conclusion, administration of saccharin sodium was effective in increasing fat and energy corrected milk yield by increasing DMI and improving rumen fermentation and antioxidant capacity of dairy goats in summer. In addition, saccharin sodium residue was undetectable in the milk.

Short chain fatty acids (SCFA) exist in dietary foods and are produced by the fermentation of gut microbiota, and are considered an important element for regulating host health. Through blood circulation, SCFA produced in the gut and obtained from foods have an impact on the intestinal health as well as vital organs of the host. It has been recognized that the gut is the “vital organ” in the host. As the gut microbial metabolites, SCFA could create an “axis” connecting the gut to other organs. Therefore, the “gut-organ axes” have become a focus of research in recent years to analyze organism health. In this review, we summarized the sources, absorption properties, and the function of SCFA in both gut and other peripheral tissues (brain, kidney, liver, lung, bone and cardiovascular) in the way of “gut-organ axes”. Short chain fatty acids exert both beneficial and pathological role in gut and other organs in various ways, in which the beneficial effects are more pronounced. In addition, the beneficial effects are reflected in both preventive and therapeutic effects. More importantly, the mechanisms behinds the gut and other tissues provided insight into the function of SCFA, assisting in the development of novel preventive and therapeutic strategies for maintaining the host health.