Gastroenteric release of methane from livestock accounts for a substantial portion of anthropogenic greenhouse gas emissions worldwide. In this study, we investigated the rumen microbiome and physiological characteristics associated with methane production in Japanese Black cattle (n = 21). Methane emissions were measured during three fattening phases—early (13 months), middle (20 months), and late (28 months). Using a mixed-effects model to consolidate period-specific measurements, animals were classified into high- and low-methane emitting groups based on residual methane emission (RME). Methane emissions in the high-methane (HME; n = 6) and low-methane (LME; n = 6) groups were 261.6 and 216.5 L/day at T1, 276.9 and 201.7 L/day at T2, and 282.9 and 221.1 L/day at T3, respectively. Overall estimated methane emissions were 273.8 L/day in the HME group and 214.4 L/day in the LME group. Hepatic transcriptome profiles, blood metabolites and hormones, rumen fermentation parameters, and rumen microbiota were subsequently analyzed to identify physiological and microbial features associated with methane emission potential. Hydrogen-sinking microbes such as Anaerovorax and Succinivibrio were present at low levels, whereas the prevalence of hydrogen-producing microbes including Christensenellaceae, Clostridium methylpentosum, and Mogibacterium was high in HME. Functional profiling of rumen microbiota revealed decreased coenzyme M biosynthesis and an increased hydrogen sink from L-glutamate biosynthesis in LME. In the liver, glutamate-derived ornithine and elevated ornithine transcarbamylase gene expression increased ammonia detoxification in LME, whereas the glutamate transporter-encoding gene SLC1A1 was upregulated in HME. These ruminal and physiological changes have potential as biomarkers for monitoring the methanogenic potential of Japanese Black cattle and highlight that the upstream oxoglutarate-to-glutamate biosynthesis pathway is associated with methane production by reducing hydrogen in the rumen.

Developmental patterns of the gut microbiota are important for improving chicken health and productivity. However, the influence of litter and litter microbes on cecal microbiota is still unclear. This study aimed to identify broiler cecal microbiota at different ages according to litter usage in cage (without litter) and conventional (with litter) conditions. The cecal contents of the broilers from each group were collected from 1-5 wk. The development and function of the gut microbiota were evaluated using 16S rRNA gene sequencing. The final body weight of the chickens was higher in the cage group than that in the conventional group. In particularly, α-diversity was higher at 3 wk than that at 1 wk. The phyla Firmicutes predominated at 3 wk. In contrast, the abundance of Bacteroidetes and fibrinolytic bacteria increased significantly at 1 and 2 wk compared to that at 3 and 5 wk. Corynebacterium was the most abundant genus in the conventional group after 3 wk. In conclusion, the cecal microbiota are influenced by environmental factors, such as cage, which improves the chicken gut environment.

Deoxynivalenol (DON) is a common mycotoxin observed in cereal grains, and feed contamination poses health risks to pigs. Biological antidotes, such as synbiotics (SYNs), have garnered attention for mitigating DON toxicity. This study aimed to assess the efficacy of SYNs by comparing the blood biochemistry, histology, and gut microbiome of weaned piglets. A 4-week trial was conducted on 32 weaned piglets. After a week of diet and environmental adaptation, the pigs were divided into four groups: (1) control (CON, n = 8); (2) SYN (n = 8); (3) DON (n = 8); and (4) DON+SYN (n = 8). The SYN supplementation of weaned piglets increased the final body weight (21.71 ± 0.93 vs. 20.73 ± 0.84), average daily gain (0.38 ± 0.02 vs. 0.34 ± 0.02), and gain-to-feed ratio (0.49 ± 0.04 vs. 0.43 ± 0.02), and decreased the feed conversion ratio (2.14 ± 0.14 vs. 2.39 ± 0.13) compared to the DON group. A high dose of DON induced liver and colon fibrosis and liver and cecum apoptosis, which were alleviated by SYNs. Glucose in the DON group (84.9 ± 3.7) was significantly lower than in the control (101.3 ± 4.2). Additionally, both the DON and DON+SYN groups exhibited higher creatine (0.9 ± 0.0 and 0.9 ± 0.1) and lower cholesterol (88.3 ± 3.2 and 90.0 ± 4.8) levels (p < 0.05). In conclusion, SYNs alleviated DON toxicity, indicating its potential as an antidote for specific biomarkers.

Taurine, biosynthesized from methionine or cysteine in the liver, plays a crucial regulatory role in bile acid conjugation, antioxidant effects, and glucose and cholesterol metabolism. This may influence the metabolic changes associated with fat accumulation in beef cattle. However, the physiological role of taurine in this species has not been fully elucidated. In this study, we explored the physiological role of taurine in Japanese Black steers (Bos taurus) in different phases during the fattening period. To examine the correlation among plasma taurine concentrations, various physiological parameters, and genes related to taurine synthesis in the liver, we used biopsied liver tissues, blood samples, and rumen fluids collected from 21 steers at three different stages, i.e., early (T1; 13 mo of age), middle (T2; 20 mo of age), and late (T3; 28 mo of age) phases. Additionally, to investigate the regulatory mechanisms underlying the expression profile of taurine synthesis genes, primary bovine hepatocytes obtained from 4-wk-old Holstein calves were treated with palmitate, oleate, acetate, propionate, or beta-hydroxybutyrate (BHBA). Plasma taurine and cholesterol concentrations significantly (P < 0.001) increased in the T2 phase, which is potentially attributable to increased energy intake and assimilation induced by increased intake of concentrated feed. Cysteine-sulfinic acid decarboxylase (CSAD) expression significantly increased (P < 0.01) in T2 than in other phases. The expression levels of cysteine dioxygenase type 1 (CDO1) and cholesterol 7 alpha-hydroxylase (CYP7A1) were significantly higher (P < 0.05) in T2 than in T3; moreover, the CDO1/glutamate-cysteine ligase catalytic subunit (GCLC) ratio was higher (P < 0.05) in T2 than in T1. Plasma taurine concentrations were positively correlated with plasma methionine (r = 0.51; P < 0.05) and total cholesterol (r = 0.56; P < 0.05) concentrations at T2. Relative CDO1 mRNA expression was upregulated in cultured bovine hepatocytes treated with oleate and propionate, whereas it was downregulated upon acetate treatment. These findings indicate that the increase in plasma taurine concentrations in the T2 phase is associated with changes in lipid and methionine metabolism in Japanese Black steers.

In Japan, Japanese Black cattle, known for their exceptional meat quality owing to their abundant intramuscular fat, undergo a unique three-stage feeding system with varying concentrate ratios. There is limited research on physiological and rumen microbial changes in Japanese Black cattle during these stages. Therefore, this study aimed to examine Japanese Black steers in these three stages: early (T1, 12–14 months), middle (T2, 15–22 months), and late (T3, 23–30 months). The rumen bacteria of 21 cattle per phase was analyzed using 16S rRNA gene sequencing. Rumen bacterial diversity was significantly higher in T1, with a distinct distribution, than in T2 and T3. Specific phyla and genera were exclusive to each stage, reflecting the shifts in feed composition. Certain genera dominated each stage: T1 had Flexilinea, Streptococcus, Butyrivibrio, Selenomonas, and Kandleria; T2 had Bifidobacterium, Shuttleworthia, and Sharpea; and T3 had Acetitomaculum, Mycoplasma, Atopobium, and Howardella. Correlation analysis revealed significant associations between certain microbial populations and physiological parameters. These findings indicate that changes in energy content and feed composition are associated with physiological and ruminal alterations. This study may guide strategies to improve rumen health and productivity in Japanese Black cattle by modifying diets to specific fattening stages.

This study proposed a method for measuring the methane (CH4 )/carbon dioxide (CO2 ) ratio from individual beef cattle under on-farm conditions and estimated the variance components of the CH4 /CO2 ratio. Gas measurements were conducted using 166 Japanese Black cattle group-housed in pens equipped with individual feed bins. The gas containing the animal's breath was measured individually after concentrate feeding by covering the feed bin with a sheet with sampling inlets. Measurements were performed six times (three consecutive days, twice daily) per individual. Most of the sampled gas contained more than 1000 ppm of the mean background-corrected CO2 , suggesting that the method proposed in this study successfully collected sufficient breath concentration to accurately measure the CH4 /CO2 ratio. The between-animal variance accounted for 31.7% of the total variance in the CH4 /CO2 ratio. The results showed that the gas collection method proposed in this study could be a useful tool for measuring the CH4 /CO2 ratio under on-farm conditions. The variance component obtained from this study will help to establish protocols for generating data for genetic evaluation and performing dietary experiments with sufficient statistical power.

This study investigated the physiological characteristics and carcass performance associated with residual methane emissions (RME), and the effects of bull differences on CH4-related traits in Japanese Black cattle. Enteric methane (CH4) emissions from 156 Japanese Black cattle (111 heifers and 45 steers) were measured during early fattening using the sniffer method. Various physiological parameters were investigated to clarify the physiological traits between the high, middle, and low RME groups. CH4-related traits were examined to determine whether bull differences affected progeny CH4 emissions. Ruminal butyrate and NH3 concentrations were significantly higher in the high-RME group than in the low-RME group, whereas the propionate content was significantly higher in the low-RME group. Blood urea nitrogen, β-hydroxybutyric acid, and insulin concentrations were significantly higher, and blood amino acids were lower in the high-RME group than in the other groups. No significant differences were observed in the carcass traits and beef fat composition between RME groups. CH4-related traits were significantly different among bull herds. Our results show that CH4-related traits are heritable, wherein bull differences affect progeny CH4 production capability, and that the above-mentioned rumen fermentations and blood metabolites could be used to evaluate enteric methanogenesis in Japanese Black cattle.

Abstract Toxicity caused by deoxynivalenol (DON) and fumonisin (FB) produced by Fusarium species, naturally occur in food and feed, can lead to repress appetite and growth inhibition in pigs. Therefore, the purpose of this study was to investigate the effect of the mycotoxin exposure with different concentrations in liver, ileum, and rectum tissues of piglets. Animals fed binary mixtures of mycotoxins followed by 0.5, 1, and 3 mg/kg feed for 30 d. The castrated pigs (Landrace × Yorkshire) were housed one per separated pen. The tissue samples were collected for nuclear magnetic resonance analysis. Additionally, biochemistry and histology were determined. Final body weight (BW) showed significant differences between the control and nine differently treated groups. In the blood biochemical analysis, the absorption of mycotoxins was significantly increased blood urea nitrogen levels. However, decreasing lipase concentrations showed in binary mixture groups. Metabolomic profiles of liver tissue were more clearly separated based on orthogonal partial least square discriminant analysis than ileum and rectum tissues. The liver (Met, Pro, Lys, and Cys), ileum (Thr, Gly, Pro and Asp), and rectum (Met, Thr, and Pro) metabolic profile revealed the potential metabolites for mycotoxin exposure, respectively. Particularly, decreasing proline concentrations at high dose (3 mg/kg) showed in liver. Whereas, two organs observed an inverse trend. In the histological analysis, Group 9 (DON 3 plus FB1 3 mg/kg) might aggravate the fibrosis in liver tissue using Masson’s trichrome stains. Contaminated with acute doses showed no dramatical changes ileum and rectum tissue. Taken together, our results indicated that low dose (0.5 mg/kg) of mycotoxin did not result in significant differences. However, high dose (3 mg/kg) of mycotoxin induced significantly toxicity causing physiological changes. In conclusion, these results suggest that the toxicity of acute exposure to binary mixture cannot be ignored in piglets, because of their effects on the liver, ileum, and rectum.

Abstract Mycotoxins causes diseases and physiological responses in humans and livestock. This study was performed to estimate the effects of binary mixtures mycotoxin {e.g., deoxynivalenol (DON) and fumonisin (FB)] on blood biochemistry, histology, and metabolic profiles in rats fed with different toxin concentrations. Experimental animals were administered by oral gavage with 0.9% saline, DON (1, 5, and 10 mg/kg BW), FB (1, 5, and 10 mg/kg) at 8 wk of age. Histological changes, metabolomic profiling, and blood biochemical analysis were performed Masson’s trichrome stain kit, liquid chromatography mass spectrometry, and VetTest chemistry analyzer, respectively. The final BW of the rats contaminated with mixtures mycotoxin significantly decreased compared with the control group. Biochemistry results and fibrosis were also significantly differentially regulated according to mycotoxin concentrations. Additionally, we observed collagen fibers in the liver and kidney showed blue staining after toxin contamination. For metabolomic profiling, data were analyzed using MetaboAnalyst 4.0. Results were analyzed by multivariate analysis to elucidate the potential compounds. The toxin-treated groups observed discriminating metabolites in the liver and kidney tissue but no differences in ileum. The profiling revealed potential metabolites such as glycine, serine and threonine metabolism. Phosphatidylethanolamine and tryptophan were identified with high sensitivity as candidate biomarkers via variable importance in the projection plot in piglets fed with mycotoxin (FDR < 0.05; P < 0.05). The differently treated groups showed discriminating metabolites in different concentrations. In conclusion, these findings suggest that mycotoxin exposure disturbs histological changes and metabolites. Dietary toxins in rats may better understand the physiological effects consistent with metabolism, which are commonly reported in animals.

Mycotoxin-contaminated feed or food can affect physiological responses and cause illnesses in humans and animals. In this study, we evaluated the effects of deoxynivalenol (DON) toxicity on the growth performance, blood biochemistry, histology, microbiome, and metabolism of rats fed with different toxin concentrations. After 1 week of acclimatization, seven-week-old male rats received 0.9% saline as a control, 0.02 mg/kg DON as T1, and 0.2 mg/kg DON as T2 via oral gavage for 4 weeks. The final body weight of the T2 group was significantly lower than that of the control and T1; however, the average daily gain, feed intake, and feed conversion ratio did not differ. Fibrosis and apoptosis were observed in various tissues as DON concentration increased. Creatinine and alkaline phosphatase levels were significantly lower in the DON-treated group than in the control. Firmicutes and Desulfobacterota phyla dominated the cecum, whereas those in the feces were Proteobacteria and Bacteroidetes. Metabolomic profiling showed phenylalanine, tyrosine, and tryptophan biosynthesis as the most prominent pathways. Overall, our results suggest that low-dose and short-term DON exposure can trigger several adverse effects in rats. Dietary toxicants in rats may explain the physiological effects associated with the metabolism commonly reported in animals.

This study was performed to investigate supplementary effects of probiotic Lacticaseibacillus paracasei NSMJ56 strain on laying performance, egg quality, intestinal histology, antioxidant status, gut immunity and microbiota in laying hens. A total of ninety-six 21-wk-old Hy-Line Brown laying hens were randomly subjected to one of 2 dietary treatments: a control group fed a non-supplemented diet, or a probiotic group fed with a diet supplemented with 1 g of Lacticaseibacillus paracasei NSMJ56 (5 × 108 CFU/kg of diet). The trial lasted for 4 wk. Egg weight was increased (P < 0.05) in laying hens fed probiotic-fed diet compared with the control group. Dietary probiotics did not affect egg quality except for Haugh unit, which was improved (P < 0.05) in the probiotic-fed group. Neither jejunal histology nor cecal short-chain fatty acids were affected by dietary treatments. Dietary probiotics increased the activity of catalase compared with the control group. Flow cytometry analysis revealed that dietary probiotics elevated the CD4+ T cells, but not CD8+ T cells, in jejunal lamina propria. Based on the LEfSe analysis at the phylum and genus levels, Erysipelotrichales, Erysipelotrichia, Flintibater, Dielma, Hespellia, Coprobacter, Roseburia, Anaerotignum, and Coprococcus were enriched in the probiotic group compared with the control group. Taken together, our study showed that dietary probiotics could be used to improve some parameters associated with egg freshness and antioxidant capacity, and to partially alter T cell population and microbial community in laying hens.

This study evaluated the effect of various growth factors and hormones in an in vitro growth (IVG) medium on the in vitro maturation (IVM) and developmental competence of oocytes derived from small antral follicles (SAFs) in pigs. Cumulus–oocyte complexes (COCs) derived from SAFs were either untreated or treated with epidermal growth factor (EGF), insulin-like factor-1 (IGF-1), insulin, or growth hormone (GH) for 2 days of IVG. Following IVG, COCs were cultured for maturation, and IVM oocytes were induced for parthenogenesis (PA). During IVG, the nuclear maturation of oocytes was significantly increased by the insulin treatment compared to other treatments. Moreover, the insulin treatment significantly increased blastocyst formation after PA relative to the No-IVG, control, EGF, and GH treatments. The cumulus expansion score after IVG-IVM was significantly higher in the insulin group than in the other groups. The glutathione (GSH) contents in IVM oocytes were increased through treatment with IGF, insulin, and GH compared to those of No-IVG oocytes. The level of reactive oxygen species (ROS) in IVM oocytes in all treatment groups was significantly lower after IVG culture than in the No-IVG group. The maturation-promoting factor (MPF) activity after IVM in the insulin-treated oocytes was significantly higher than that of the oocytes treated with EGF, IGF-1, and GH. In conclusion, this study demonstrates that insulin treatment during IVG culture improves the maturational and developmental competence of oocytes derived from SAFs in pigs through its effect on cumulus cell expansion and cytoplasmic microenvironments, such as GSH, ROS, and MPF activity.

This study aimed to identify the growth performance and blood factors associated with carcass weight in Japanese Black calves based on 675 performance tests and field carcass records. We measured the body weight, withers height, and chest girth at the start of fattening age (approximately 8-10 months) and analyzed eight blood factors, including vitamins and metabolites. Single- and two-trait animal models were used to estimate the heritability and genetic correlations. The heritability estimates for growth performance were moderate to high (ranging from 0.48 to 0.74), and those for blood metabolites were low to moderate (ranging from 0.19 to 0.51). Estimates for genetic correlations of carcass or body weight with body weight, withers height, and chest girth were high (ranging from 0.42 to 0.80). The body weight and withers height at 8 months of age are possibly closely related to the final carcass weight. The blood metabolites associated with body weight were vitamin E in steers (castrated males) and β-carotene in heifers. Our findings indicate that body measurements and blood metabolites measured during the growing period could be used to determine the nutritional and physiological status of cattle as well as predict carcass weight.

This study aimed to evaluate the effects of dietary Chlorella vulgaris (CV) on the distribution of immune cells, intestinal morphology, intestinal barrier function, antioxidant markers, and the cecal microbiome in 10-day-old broiler chickens. A total of 120 day-old Ross 308 male broiler chicks were assigned to two dietary treatments using a randomized complete block design, with body weight as the blocking factor. Birds fed a diet containing CV showed an increase in CD4+ T cells (p < 0.05) compared to those fed the control diet. The relative mRNA expression of intestinal epithelial barrier function-related markers (occludin and avian β-defensin 5) was elevated (p < 0.05) in the CV-supplemented group compared to the control group. The alpha diversity indices (Chao1 and observed features) of the cecal microbiome in 10-day-old birds increased (p < 0.05), indicating higher richness within the cecal bacterial community. In the microbiome analysis, enriched genera abundance of Clostridium ASF356 and Coriobacteriaceae CHKCI002 was observed in birds fed the diet containing CV compared to those fed the control diet. Taken together, dietary CV supplementation might alter intestinal barrier function, immunity, and microbiomes in 10-day-old broiler chickens.

This study aimed to investigate the relationship between rumen microbiota and physiological characteristics in Japanese Black cattle during the fattening period, which are known for their distinctive physiological characteristics due to prominent intramuscular fat deposition. The experimental period was categorized into three stages: early (12 to 14 months of age; T1), middle (15 to 22 months; T2), and late fattening phases (23 to 30 months; T3). We analyzed the rumen microbiota of 21 Japanese Black cattle in each phase using 16S rRNA gene amplicon sequencing. In addition, we examined the correlation between the rumen microbiota and various physiological parameters, such as blood metabolites, hormones, and rumen fermentation characteristics. Our results showed that rumen microbial diversity was greater in T1, and the inter-group distribution of rumen microbiota in T1 was differentiated from T2 and T3. At the genus level, Flexilinea, Streptococcus, Butyrivibrio, Selenomonas and Kandleria were the most abundant in T1. Bifidobacterium, Shuttleworthia and Sharpea were the most abundant in T2. Acetitomaculum, Mycoplasma, Atopobium and Howardella were the most abundant in T3. In correlation analysis, Monoglobus and Olsenella negatively correlated with IGF-1 and positively correlated with cortisol in T1. Firmicutes/Bacteroidota ratio positively correlated with daily gain, blood total cholesterol, and lactic acid dehydrogenase in T3. Planctomycetota correlated with volatile fatty acid components during the entire period, while Verrucomicrobiota positively correlated with carcass traits in T1. Additionally, functional genetic profiles indicated that rumen microbiota related to carbohydrate metabolism and nucleotide biosynthesis was significantly enriched in T1 and T3, respectively. The composition of rumen microbial in Japanese Black cattle varied depending on fattening stages, and this variation is likely attributable to changes in feed composition. Furthermore, specific microorganisms were significantly associated with physiological parameters. Our findings could help in the development of strategies to enhance gut health and productivity by manipulating the rumen microbiota through the changes in diet compositions considering the fattening stages of Japanese Black cattle.

Angiopoietin-like protein 3 (ANGPTL3) is expressed predominantly in the liver and plays a major role in regulating the circulating triglyceride and lipoprotein fraction concentrations by inhibiting lipoprotein lipase (LPL) activity. Given these physiological roles, ANGPTL3 may play an important role in metabolic changes related to fat accumulation during the fattening period in Japanese Black. This study aimed to reveal the physiological roles of hepatic ANGPTL3 in Japanese Black steers (Bos taurus) during the fattening period and investigate the regulatory effects of hepatic ANGPTL3. To investigate the gene expression and protein localization of ANGPTL3, 18 tissue samples were collected from tree male Holstein bull calves aged 7 wk. Biopsied liver tissues and blood samples were collected from 21 Japanese Black steers during the early (T1; 13 mo of age), middle (T2; 20 mo), and late fattening phases (T3; 28 mo). Relative mRNA expression, blood metabolite concentrations, hormone concentrations, growth, and carcass traits were analyzed. To identify the regulatory factors of hepatic ANGPTL3, primary bovine hepatocytes collected by two Holstein calves aged 7 wk were incubated with insulin, palmitate, oleate, propionate, acetate, or beta-hydroxybutyric acid (BHBA). The ANGPTL3 gene was most highly expressed in the liver, with minor expression in the renal cortex, lungs, reticulum, and jejunum in Holstein bull calves. In Japanese Black steers, relative ANGPTL3 mRNA expressions were less as fattening progressed, and blood triglyceride, total cholesterol, and nonesterified fatty acid (NEFA) concentrations increased. Relative ANGPTL8 and Liver X receptor alpha (LXRα) mRNA expressions decreased in late and middle fattening phases, respectively. Furthermore, relative ANGTPL3 mRNA expression was positively correlated with ANGPTL8 (r = 0.650; P < 0.01) and ANGPTL4 (r = 0.540; P < 0.05) in T3 and T1, respectively, and LXRα showed no correlation with ANGPTL3. Relative ANGTPL3 mRNA expression was negatively correlated with total cholesterol (r = -0.434; P < 0.05) and triglyceride (r = -0.645; P < 0.01) concentrations in T3 and T1, respectively; There was no significant correlation between ANGTPL3 and carcass traits. Relative ANGTPL3 mRNA expression in cultured bovine hepatocytes was downregulated in oleate treatment. Together, these findings suggest that ANGPTL3 downregulation in late fattening phases is associated with the changes in lipid metabolism.

This study investigated the effect of exposure to flutriafol based on residues in pigs. Pigs were exposed to different concentrations (0.313, 0.625, 3.125, 6.25, and 12.5 mg/kg bw/d, n=20) for 4 wk in different treatment groups. Serum biochemical analysis, residue levels, and histological analysis were conducted using the VetTest chemistry analyzer, liquid chromatography mass spectrometry, and Masson's trichrome staining, respectively. The body weight (initial and final) was not significantly different between groups. Parameters such as creatinine, blood urea nitrogen, alanine aminotransferase, and lipase levels were significantly different as compared to the control group. Flutriafol increased the residue limits in individual tissue of the pigs in a dose dependent manner. Flutriafol exposures indicated the presence of fibrosis, as confirmed from Masson's trichrome staining. These results suggest that flutriafol affects the morphology and serum levels in pigs. The dietary flutriafol levels can provide a basis for maximum residue limits and food safety for pork and related products.