Diarrhea is the leading cause of mortality in postnatal goat kids, seriously impacting breeding efficiency. This study aimed to explore the effects of Bacillus pumilus 315 (B. pumilus) on goat kids’ diarrhea and its regulatory mechanism. Thirty-six 1-day-old goat kids were assigned into four treatments, the control (CON) group and low-, medium- and high-dose groups supplemented with B. pumilus at 1 × 10⁸ (BP1), 5 × 10⁸ (BP5), and 1 × 10⁹ CFU/d (BP10). Each group consisted of 9 replicates with 1 goat kid per replicate. The results showed that the incidence of diarrhea and fecal scores decreased significantly (P < 0.05). A dose of 5 × 10⁸ CFU/d B. pumilus reduced pro-inflammatory factors (including tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], interleukin-6 [IL-6], P < 0.05), increased the expression levels of anti-inflammatory factors (including transforming growth factor-β [TGF-β], peroxisome proliferate-activated receptor-gamma [PPAR-γ], interleukin-10 [IL-10], P < 0.05), immune indicators (including immunoglobulin G [IgG], immunoglobulin A [IgA], immunoglobulin M [IgM], secretory immunoglobulin A [sIgA], P < 0.05) and antioxidant indicators (including total antoxidative capacity [T-AOC], superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], catalase [CAT], P < 0.05) in both jejunum and colon, and ultimately improved the barrier function of the jejunum and colon mucosa. The enhanced gut immunity and barrier function were associated with increased abundance of Enterococcus and Lactobacillus (P < 0.05) and decreased abundance of Campylobacter and Escherichia-Shigella (P < 0.05). In conclusion, dietary addition of B. pumilus may improve gut health by modulating the composition and function of the flora, ultimately alleviating diarrhea in goat kids.

The objectives of the experiment were to compare the effects of rumen-protected taurine (RPT) and rumen-protected methionine (RPM) on the nitrogen (N) metabolism, plasma biochemical parameters, and metabolomics in beef steers and to clarify whether taurine plays similar roles as methionine (Met) in the regulation of N metabolism in beef steers. Six Simmental steers aged 12 months (liveweight 325 ± 7 kg) were used as experimental animals. The experimental treatments included a basal diet, the basal diet + 70.0 g/d RPT and the basal diet + 74.2 g/d RPM. The treatments were assigned in a replicated 3 × 3 Latin square design. Each experimental period included 15 d for adaptation and 5 d for sampling. The results showed that supplementing the diet with RPT or RPM did not affect the apparent nutrient digestibility (P > 0.05). Supplementing the diet with RPT or RPM increased the N retention (P < 0.05) and the N utilization efficiency (NUE) (P < 0.05) and decreased the urinary excretion of 3-methylhistidine (P < 0.05) and the estimated skeletal protein degradation rate (P < 0.05). Supplementing the diet with RPT increased the plasma concentrations of taurine (P < 0.001), cysteine (P = 0.010), valine (P = 0.013) and total non-essential amino acids (NEAA) (P = 0.047) and tended to increase the plasma concentrations of essential amino acids (EAA) + NEAA (P = 0.087), but it did not affect the plasma concentrations of total EAA (P > 0.05). Supplementing the diet with RPM increased the plasma concentrations of methionine (P = 0.033), lysine (P = 0.047), cysteine (P = 0.007), leucine (P = 0.046), isoleucine (P = 0.046), valine (P = 0.034), total EAA (P = 0.028), total NEAA (P = 0.004) and EAA + NEAA (P = 0.004). The plasma metabolomics profiling revealed that supplementing the diet with RPT upregulated the plasma concentrations of taurine (P < 0.001), L-cysteine (P = 0.004) and some amino acid (AA) analogues (P < 0.05) and RPM upregulated the plasma concentrations of Met (P = 0.021), L-isoleucine (P = 0.036), L-tryptophan (P = 0.006) and some AA analogues (P < 0.05). In conclusion, taurine has similar impacts to Met in improving the N retention and the NUE in beef steers. Taurine deficiency negatively affects the NUE of beef steers. Supplementation of the diet with taurine is beneficial to the N utilization in beef steers.

This study evaluated the effect of maternal glycerol monolaurate (GML) supplementation during late gestation and lactation on sow reproductive performance, transfer of immunity and redox status, milk fat and fatty acid profile, and fecal microbiota. Eighty multiparous sows (Landrace × Large white) were randomly allocated to two treatment groups (with or without 1000 mg/kg GML) with 40 replicates per treatment. The feeding experiment lasted from d 85 of gestation (G85) to d 23 of lactation (L23). The samples were collected on d 1 (L1) and 21 (L21) of lactation. Our results showed that maternal GML supplementation significantly increased litter weight (P = 0.002), average daily gain of piglets (P = 0.048), and sow average daily feed intake (P = 0.032). Compared with CON group, the concentrations of lauric acid (C12:0; P = 0.022), C16:0 (P = 0.001), and total saturated fatty acids (P = 0.006) in colostrum as well as C12:0 in L21 milk (P = 0.001) were higher in GML group. Besides, the concentrations of immunoglobulin A (IgA) and IgG in colostrum as well as sow and piglet plasma, the total antioxidant capacity and superoxide dismutase activity in sow colostrum were also significantly higher in the GML group (P < 0.05). Microbiome results showed that GML addition increased fecal microbial alpha diversity as well as the relative abundances of short chain fatty acids producing bacteria Ruminococcaceae and Parabacteroides; and decreased the harmful Proteobacteria of sows (P < 0.05). The Spearman analysis showed that the microbial biomarkers Prevotellaceae, Ruminococcaceae, and Parabacteroides were positively correlated with IgA and IgG of sow plasma and milk (P < 0.05). Besides, maternal GML addition up-regulated the relative protein expressions of proliferating cell nuclear antigen, cyclin D1, G protein-coupled receptor 84 (GPR84) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in the duodenum and jejunum of piglets. Collectively, current findings suggested that maternal GML supplementation enhanced piglet growth during lactation, which might be associated with improving milk fat and lauric acid contents, microbiota derived immunoglobulins transfer, and gut health through potential involvement of GPR84 and PI3K/Akt signaling pathway.

An inadequate amino acid (AA) supply in animals under protein-restricted conditions can slow skeletal muscle growth. Protein translation can be activated by short-term leucine (Leu) stimulation; however, whether muscle mass increases under long-term Leu supplementation and how the gut and muscle respond to Leu supplementation are largely unknown. In this study, we investigated if muscle mass increases with long-term Leu supplementation under protein-restricted conditions. We identified changes in the link between the gut and muscles under different amino acid supply conditions, using goats as the study object. A total of 27 Xiangdong black male goats with average initial body weight (BW) of 10.88 ± 1.22 kg were randomly divided into three dietary treatments: a normal protein diet (NP, 14.24% crude protein [CP]); a low protein diet (LP, 8.27% CP with supplemental 1.66% rumen-protected lysine [RPLys] and 0.09% rumen-protected methionine [RPMet]); and LP diet with rumen-protected Leu (RPLeu) (LP + RPLeu, 8.75% CP with supplemental 1.66% RPLys, 0.09% RPMet and 1.46% RPLeu). The animal trial lasted for 110 d, consisting of 20 d of adaptation and a 90 d of experimental period. The results showed that long-term protein restriction increased gut tryptophan hydroxylase 1 (TPH1) activity (P < 0.001), tryptophan (Trp) catabolism (P < 0.001), and 5-hydroxytryptamine (5-HT) synthesis (P < 0.001), which all subsequently reduced goat appetite. Long-term Leu supplementation inhibited 5-HT synthesis (P < 0.001), decreased Trp catabolism in the gut, and increased appetite in goats. Long-term protein restriction enhanced jejunal and ileal branched-chain amino acid transferase (BCAT) (P < 0.001) and branched-chain α-Keto acid dehydrogenase (BCKD) (P = 0.048) activities, which increased branched-chain amino acid (BCAA) catabolism. Immunofluorescence results showed that protein restriction decreased the intestinal mucosal expression of solute carrier family 1 member 5 (SLC1A5) (P = 0.032) and solute carrier family 7 member 5 (SLC7A5) (P < 0.001), reduced BCAA transport from the mucosa to the blood, lowered BCAA levels in the blood (P < 0.001). Western blot results showed that protein restriction inhibited mammalian target of rapamycin (mTOR) pathway activation in goat muscles. Leu supple-mentation increased BCAA translocation from the intestine to the blood and promoted activation of the muscle mTOR pathway and protein synthesis. In conclusion, our results suggest that Leu supplementation in low-protein diets improves appetite and alleviates the inhibition of muscle protein synthesis in goats.

Increasing forage proportion (FP) in the diets of dairy cows would reduce competition for human edible foods and reduce feed costs, particularly in low-input systems. However, increasing FP reduces productivity and may increases methane (CH₄) emission parameters. This work aimed to investigate the impact of FP and breed on feed efficiency and CH₄ emission parameters. Data from 32 individual experiments conducted at the Agri-Food and Biosciences Institute between 1992 and 2010 were utilised in this study resulting in data from 796 Holstein-Friesian (HF), 50 Norwegian Red (NR), 46 Jersey × HF (J × HF) and 16 NR × HF cows. Diets consisted of varying proportions of forage and concentrate dependent on the experimental protocols of each experiment. A linear mixed model was used to investigate the effect of low (LFP; 10% to 30%), medium (MFP; 30% to 59%), high (HFP; 60% to 87%) and pure (FOR; 100%) FP (dry matter [DM] basis) and breed on feed efficiency, and CH₄ emission parameters and multivariate redundancy analysis identified associations between animal and dietary drivers on the same variables. Total dry matter intake (DMI) was higher for cows offered LFP (17.3 kg/d) and MFP (17.9 kg/d) compared to HFP (15.3 kg/d) and FOR (13.8 kg/d) (P < 0.001). Milk yield (P < 0.001), milk yield/DMI (P < 0.001), energy corrected milk (ECM)/DMI (P < 0.001) and milk energy/DMI (P < 0.001) were higher for LFP and MFP compared to HFP and FOR. Methane/DMI was higher for HFP (24.3 g/kg) compared to MFP (22.4 g/kg) (P < 0.001). Methane/milk yield (P < 0.001) or CH₄/ECM (P < 0.001) was higher for HFP (22.5 or 21.6 g/kg) and FOR (27.0 or 25.8 g/kg) compared to MFP (19.1 or 17.9 g/kg). There were no differences between LFP and MFP or between HFP and FOR for milk yield, milk yield/DMI, ECM/DMI, milk energy/DMI, CH₄/milk yield and CH₄/ECM (P > 0.05). Differences existed between breeds for residual feed intake (P = 0.040), milk yield/DMI (P = 0.041) and CH₄/DMI (P = 0.048) with multivariate redundancy analysis demonstrating negative correlations with efficiency and positive correlations with CH₄/DMI and CH₄/milk yield. Feeding concentrates at 70% to 90% of DMI (LFP group) would not result in any further benefits for productivity, feed efficiency or CH₄ yield and intensity when compared to feeding 41% to 70% concentrates of DMI (MFP group). There may be opportunity to improve profitability for lower intensity farms with less concentrate input.

This study investigated the effect of peroxidized lipids on piglets' growth performance, intestinal morphology, inflammatory reactions, oxidative stress in the liver, duodenum, jejunum, ileum, and colon, and ileal microbiota. Twenty piglets (Duroc × [Landrace × Yorkshire]; age = 21 d old, BW = 6.5 ± 1 kg) were randomly assigned to two groups with 10 replicates per group and one piglet per replicate. The control group was fed 6% fresh soybean oil and the peroxidized soybean oil (PSO) group fed 6% PSO. The experimental feeding period lasted 24 d. The study found no impact on ADFI, ADG and gain to feed ratio (P > 0.05). However, the PSO group increased the diarrhea index and the serum levels of lactate dehydrogenase triglycerides, cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (P < 0.05), along with decreased concentrations of alanine aminotransferase and blood urea nitrogen (P < 0.05). For oxidative enzymes, PSO increased the concentration of F2-isoprostane in urine (P = 0.032), malondialdehyde (MDA) in the duodenum (P = 0.001) and jejunum (P = 0.004), decreased thiobarbituric acid reactive substances (TBARS) in the liver (P = 0.001) but increased TBARS in duodenum (P = 0.001), and carbonylated proteins in the duodenum (P = 0.003). For antioxidant enzymes, PSO decreased superoxide dismutase (SOD) in the liver (P = 0.001), colon (P = 0.002), and jejunum (P = 0.015), along with glutathione peroxidase (GSH-Px) in the liver (P = 0.008) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in ileum (P = 0.001). For inflammatory reactions, PSO increased interleukin (IL)-1β concentrations in the duodenum and colon, and IL-10 in the jejunum, while decreasing IL-4 concentration in the duodenum (P < 0.05). For intestinal morphology and ileal microbiota, PSO increased ileal crypt depth, while decreasing the crypt-to-villus ratio (P < 0.05). Peroxidized soybean oil increased the relative abundance of Prevotella, Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_6, Pasteurella and Klebsiella (P < 0.05). In conclusion, this study revealed that PSO worsened diarrhea, increasing the ileal crypt depth and the relative abundance of harmful microbiota, and induced oxidative stress and inflammation in the intestines and liver, primarily in the jejunum and ileum.

The inclusion of various forages in a normal forage-to-concentrate ratio has widely been reported to reveal the changes that occur in the foregut tissues. However, the mechanism by which the wheat straw, alfalfa hay, or both alter the orchestrated crosstalk of microbiome and host-transcriptome in the rumen of lambs fed a high-concentrate diet is elusive. Sixty-three Hulunbuir lambs were randomly allotted to 3 dietary groups, and each dietary group had 3 pens with 7 lambs. The lambs were fed high-concentrate diets (70%) supplemented with either 30% wheat straw (30S), a mixture of 15% alfalfa hay and 15% wheat straw (30M), or 30% alfalfa hay (30A) over a 2-week adaptation period and a 12-week formal trial. Compared with the 30S and 30A groups, the 30M group had greater (P < 0.05) levels of plasma glucagon-like peptide (GLP-2), interleukin-2 (IL-2). Humoral immunity showed a tendency to increase in the 30M group, as evidenced by the greater levels of plasma immunoglobulins (Ig) A and IgG (P > 0.05). The 16S rRNA result showed that the abundance of Lachnospiraceae (NK3A20 group and unclassified), Olsenella, Shuttleworthia, and Succiniclasticum were enriched in the 30M group. Meanwhile, the abundances of Ruminococcaceae NK4A214 and prevetolla_7 were enriched in 30S and 30A, respectively. The RNA-seq identified 35 shared differentially expressed genes (DEGs) between the "30S vs. 30M" and "30S vs. 30A," enriched in lipid metabolism pathways, including glycerophospholipid and arachidonic acid metabolism. The weighted gene co-expression network analysis results revealed that the expression of genes in the darkred (194 genes) and darkgreen (134 genes) modules showed a strong positive correlation with phenotypic traits and bacterial genera, respectively. The genes in the darkgreen module were involved in carbohydrate, lipid, and amino acid metabolism and showed a wide range of associations with Prevotella_7, Shuttleworthia, and Succiniclasticum, indicating that ruminal microbes might act as a vital driver in the microbiome-host interaction, likely through fermentation of end-products or metabolites. In conclusion, the results indicate that microbiome enrichment in response to feeding wheat straw and alfalfa hay might drive microbiome-host crosstalk to regulate rumen function in lambs fed a high-concentrate diet.

This study aimed to evaluate the effects of dietary geniposide supplementation on growth performance, lipid metabolism, health status, and ammonia stress resistance in turbot (Scophthalmus maximus). Four hundred fifty fish were randomly allocated into 5 treatments with triplicate tanks (30 fish per tank). They were hand-fed to apparent satiety for 56 d with a basal diet (GP0) or diets containing 100, 200, 400, and 800 mg/kg geniposide (termed as GP100, GP200, GP400, GP800, respectively). After the conclusion of the feeding trial, the fish were exposed to ammonia stress for 96 h. The results showed that the growth performance were not affected by geniposide (P > 0.05). Dietary supplementation with geniposide decreased crude lipid in viscera without liver, subcutaneous adipose tissue (SAT), and the liver, as well as triglyceride concentrations in plasma, the liver and SAT (P < 0.05). Dietary supplementation with 400 and 800 mg/kg geniposide significantly down-regulated lipogenesis-related gene expression, as well as fatty acid uptake-related gene expression, while significantly up-regulated triglyceride secretion-related gene expression in the liver compared with the control group (P < 0.05). The GP800 group exhibited a significant reduction in plasma malondialdehyde contents compared with the control group, while both the GP200 and GP800 groups showed a significant increase in plasma complement C3 activities (P < 0.05). Furthermore, there was a notable enhancement in plasma lysozyme and total superoxide dismutase levels in the geniposide supplemented groups compared to the control group (P < 0.05). Additionally, a significant decrease in the mRNA level of pro-inflammatory cytokine and a remarkable increase in the mRNA expression of anti-inflammatory cytokines were discovered in geniposide supplemented groups relative to the control group (P < 0.05). Cumulative survival rates after ammonia stress in the GP400 and GP800 groups were statistically higher than that in the control group (P < 0.05). In conclusion, dietary geniposide supplementation could reduce lipid deposition in turbot by regulating lipid metabolism and transportation, and remarkably enhance immunity, antioxidant ability, and resistance to ammonia stress in turbot. Based on the quadratic regression analyses, the optimal concentrations of geniposide were estimated to be 545.21 to 668.41 mg/kg feed.

An 8-week feeding trial was conducted to investigate the effects of replacing dietary fish oil (FO) with black soldier fly larval oil (BSFO) on growth performance, antioxidant and immune response, lipid metabolism and mitochondrial function of the juvenile mud crab. A total of 160 mud crabs (18.58 ± 0.02 g) were randomly distributed into five treatments spread across 160 aquaria. There were 4 replicates per treatment and 8 crabs per replicate. The basal diet (Control) contained 3% fish oil and fish oil was replaced with BSFO at 25%, 50%, 75%, and 100% in the remaining four treatments. The results showed that when the proportion of BSFO replacing FO was less than 50%, there were no significant differences in percent weight gain (PWG), specific growth rate (SGR) and feed efficiency (FE) between the experimental and the control groups (P > 0.05); however, PWG and SGR decreased as the percentage of substitution increased from 50% to 100% (P < 0.01). When the percentage of substitution was less than 50%, the expression levels of genes related to lipid synthesis and catabolism were significantly up-regulated and down-regulated, respectively (P < 0.05). When 25% and 50% FO were replaced with BSFO, the antioxidant and immune responses enhanced (P < 0.05), and antioxidant and immune-related enzyme activities and metabolite concentrations in the hemolymph and hepatopancreas significantly increased (P < 0.05), and the concentrations of malondialdehyde (MDA) and protein carbonyl (PC), and the apoptosis index in the hepatopancreas significantly decreased (P < 0.05). Moreover, mitochondrial function indexes in the hepatopancreas, such as mitochondrial DNA copy number and expression levels of energy metabolism-related genes were significantly up-regulated (P < 0.05). Hepatopancreas mitochondria were more abundant in crabs fed diets with 25% and 50% replacement of FO with BSFO, while adenosine triphosphate content was the highest in 25% FO replacement group (P = 0.003). In summary, the results of the present study demonstrated that the replacement of FO with BSFO at less than 50% (i.e. in-feed BSFO level of 1.5%) did not negatively affect the growth performance of mud crabs, and could improve the antioxidant capacity, immune response, and enhance mitochondrial function.

Antarctic krill meal (KM) (Euphausia superba) as a substitute for fishmeal in aquatic animal diets is gaining popularity worldwide. A quantitative approach investigating the efficacy of using this protein on the production performance of aquatic animals remains widely limited. Here, we employed a meta-analysis to quantify the overall effects (Hedges’g [g] value effect size) of KM on the specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), and survival rate (SR) of several aquaculture species. A total of 22 records published during 2006 to 2022 from different countries, targeting 14 aquatic species, were employed in the present study. Overall, KM has a high nutritional value relative to fishmeal, particularly from the high protein and amino acid composition. Dietary KM significantly increased the overall effect size of SGR (g = 1.92) (P = 0.001); the positive effect was illustrated in marine species (g = 1.32 to 9.10) (P < 0.05) and sturgeon (Acipenser gueldenstaedtii) (g = 6.59) (P < 0.001). The overall g value for FCR (–2.42) was significantly improved compared to the control group (P < 0.001). The inclusion of KM in aquatic animal diets did not affect g value of PER (1.52, 95% confidence interval: –1.04 to 4.07) and survival rate (0.08, 95% confidence interval: –0.63 to 0.79) (P = 0.252 and 0.208, respectively). The meta-regression models indicated that SGR of rainbow trout (Oncorhynchus mykiss) was significantly correlated with dietary KM by a positive linear model (P = 0.022). The cod and sturgeon (A. gueldenstaedtii) appeared to efficiently utilize krill-containing diets as illustrated by a negative linear model (P = 0.011 and P = 0.024, respectively) between dietary KM and FCR. Dietary KM positively correlated with PER for Atlantic cod (P = 0.021). Our meta-analysis highlighted the significant outcome of KM in diets for aquaculture species by reducing pressure on forage fish from marine resources and sparing edible foods. Specifically, including KM significantly reduced economic fish-in fish-out (eFIFO) in four taxa—the top forage fish consumers (P < 0.05): marine fish, salmon, shrimp, and trout. The meta-analysis revealed the decreased food-competition feedstuff in diets for important aquaculture species (P < 0.05) fed dietary KM. The outlook for efficient use of KM from marine resources in aquafeeds was elucidated in the present work.