Effects of dietary palmitic acid and oleic acid ratio on milk production, nutrient digestibility, blood metabolites, and milk fatty acid profile of lactating dairy cows.

Adequate energy supply is a crucial factor for maintaining the production performance in cows during the early lactation period. Adding fatty acids (FA) to diets can improve energy supply, and the effect could be related to the chain length and degree of saturation of those FA. This study was conducted to evaluate the effect of different ratios of palmitic acid (C16:0) to oleic acid (cis-9 C18:1) on the production performance, nutrient digestibility, blood metabolites, and milk FA profile in early lactation dairy cows. Seventy-two multiparous Holstein cows (63.5 ± 2.61 days in milk) blocked by parity (2.39 ± 0.20), body weight (668.3 ± 20.1 kg), body condition score (3.29 ± 0.06), and milk yield (47.9 ± 1.63 kg) were used in a completely randomized design. Cows were divided into 3 groups with 24 cows in each group. Cows in the 3 treatment groups were provided iso-energy and iso-nitrogen diets, but the C16:0 to cis-9 C18:1 ratios were different: (1) 90.9% C16:0 + 9.1% cis-9 C18:1 (90.9:9.1); (2) 79.5% C16:0 + 20.5% cis-9 C18:1 (79.5:20.5); and (3) 72.7% C16:0 + 27.3% cis-9 C18:1 (72.7:27.3). Fatty acids were added at 1.3% on a dry matter basis. Although the dry matter intake fat-corrected milk yield and energy-corrected milk yield were not affected, the milk yield, milk protein yield, and feed efficiency increased linearly with increasing cis-9 C18:1 ratio. The milk protein percentage and milk fat yield did not differ among treatments, whereas the milk fat percentage tended to decrease linearly with the increasing cis-9 C18:1 ratio. The lactose yield increased linearly and lactose percentage tended to increase linearly with increasing cis-9 C18:1 ratio, but the percentage of milk total solids and somatic cell count decreased linearly. Although body condition scores were not affected by treatments, body weight loss decreased linearly with increasing cis-9 C18:1 ratio. The effect of treatment on nutrient digestibility was limited, except for a linear increase in ether extract and neutral detergent fiber digestibility with increasing cis-9 C18:1 ratio. There was a linear increase in the concentration of plasma glucose, but the triglyceride and nonesterified FA concentrations decreased linearly with increasing cis-9 C18:1 ratio. As the cis-9 C18:1 ratio increased, the concentration of de novo FA decreased quadratically, but the mixed and preformed fatty acids increased linearly. In conclusion, increasing cis-9 C18:1 ratio could increase production performance and decrease body weight loss by increasing nutrient digestibility, and the ratio that had the most powerful beneficial effect on early lactation cows was 72.7:27.3 (C16:0 to cis-9 C18:1).

Effect of active dry yeast on lactation performance, methane production, and ruminal fermentation patterns in early-lactating Holstein cows.

This study was conducted to examine the effect of active dry yeast (ADY) supplementation on lactation performance, ruminal fermentation patterns, and CH4 emissions and to determine an optimal ADY dose. Sixty Holstein dairy cows in early lactation (52 ± 1.2 DIM) were used in a randomized complete design. Cows were blocked by parity (2.1 ± 0.2), milk production (35 ± 4.6 kg/d), and body weight (642 ± 53 kg) and assigned to 1 of 4 treatments. Cows were fed ADY at doses of 0, 10, 20, or 30 g/d per head for 91 d, with 84 d for adaptation and 7 d for sampling. Although dry matter intake was not affected by ADY supplementation, the yield of actual milk, 4% fat-corrected milk, milk fat yield, and feed efficiency increased quadratically with increasing ADY supplementation. Yields of milk protein and lactose increased linearly with increasing ADY doses, whereas milk urea nitrogen concentration and somatic cell count decreased quadratically. Ruminal pH and ammonia concentration were not affected by ADY supplementation, whereas ruminal concentration of total volatile fatty acid increased quadratically. Digestibility of dry matter, organic matter, neutral detergent fiber, acid detergent fiber, nonfiber carbohydrate, and crude protein increased quadratically with increasing ADY supplementation. Supplementation of ADY did not affect blood concentration of total protein, triglyceride, aspartate aminotransferase, and alanine aminotransferase, whereas blood urea nitrogen, cholesterol, and nonesterified fatty acid concentrations decreased quadratically with increasing ADY supplementation. Methane production was not affected by ADY supplementation when expressed as grams per day or per kilogram of actual milk yield, dry matter intake, digested organic matter, and digested nonfiber carbohydrate, whereas a trend of linear and quadratic decrease of CH4 production was observed when expressed as grams per kilogram of fat-corrected milk and digested neutral detergent fiber. In conclusion, feeding ADY to early-lactating cows improved lactation performance by increasing nutrient digestibility. The optimal ADY dose should be 20 g/d per head.

Vitamin E regulates bovine granulosa cell apoptosis via NRF2-mediated defence mechanism by activating PI3K/AKT and ERK1/2 signalling pathways.

High-yield dairy cows are usually subject to high-intensive cell metabolism and produce excessive reactive oxygen species (ROS). Once ROS is beyond the threshold of scavenging ability, it can induce oxidative stress, imperilling the reproductive performance of cows. The study was to investigate the effects of vitamin E (VE) on H2 O2 -induced proliferation and apoptosis of bovine granulosa cells and the underlying molecular mechanism. Granulosa cells were pretreated with VE for 24 hr and then treated with H2 O2 for 6 hr. The results showed that VE treatment decreased the intracellular ROS levels, increased the MDA content, and improved the antioxidant enzyme activity in a dose-dependent manner. Furthermore, VE treatment promoted the proliferation and inhibited apoptosis in granulosa cells by up-regulation of CCND1 and BCL2 levels and down-regulation of P21, BAX, and CASP3 levels. The cytoprotective effects of VE were attributed to the activation of the NRF2 signalling pathway. Knockdown of the NRF2 impaired the cytoprotective effects of VE on granulosa cells. Besides, the PI3K/AKT and ERK1/2, but not the p38 signalling pathway is involved in the regulation of VE-mediated cell proliferation and apoptosis. The PI3K/AKT inhibitor LY294002 and ERK1/2 inhibitor SCH772984 inhibited the VE-induced granulosa cell proliferation and promoted apoptosis, whereas the p38 inhibitor SB203580 had the opposite effects. These results were confirmed by proliferation and apoptosis-related gene expression at mRNA and protein levels. The results also showed that the PI3K/AKT inhibitor LY294002 and ERK1/2 inhibitor SCH772984 inhibited VE-induced NRF2, GCLC, GCLM, and HO-1 expression, whereas the p38 inhibitor SB203580 not. Overall, the results demonstrated that VE-regulated granulosa cell proliferation and apoptosis via NRF2-mediated defence system by activating the PI3K/AKT and ERK1/2 signalling pathway.

Effects of prepartum zinc-methionine supplementation on feed digestibility, rumen fermentation patterns, immunity status, and passive transfer of immunity in dairy cows.

The aim of this study was to determine the effects of prepartum supplementation of zinc-methionine (Zn-Met) on feed digestibility, rumen fermentation patterns, and immunity status in dams and passive immunity transfer in their calves. A randomized complete design was used in this study. Forty multiparous Holstein dairy cows in late pregnancy (60 d before the expected calving date) were blocked by parity (2.1 ± 0.3), body weight (651 ± 52 kg), and expected calving date, and randomly assigned to 1 of 4 treatments. Cows were supplemented with Zn as Zn-Met at 0, 20, 40, or 60 mg/kg of dry matter (DM) from 60 d before expected calving date to the calving day. Though the nutrient digestibility was not affected by Zn supplementation, DM intake, Zn digestibility, and Zn deposition increased linearly with increasing Zn-Met supplementation. Ruminal pH and molar proportion of individual volatile fatty acids were similar, whereas a linear decrease and increase were observed in ruminal ammonia and microbial crude protein concentration, respectively, with increasing Zn-Met supplementation. Maternal serum concentration of alkaline phosphatase, carboxypeptidase, Cu and Zn superoxide dismutase, and total antioxidant capacity were greater in cows supplemented with >40 mg of Zn/kg of DM compared with the control group. With increasing Zn-Met supplementation, maternal blood concentration of IL-1 decreased linearly, whereas IL-2 and IL-6 increased linearly, and no differences were observed in IL-4. Concentration of nonesterified fatty acids and ß-hydroxybutyric acids in maternal blood was similar between treatments. No difference was observed in colostrum composition with increasing Zn-Met supplementation. Concentration of Zn and immunoglobulins (including IgA, IgG, and IgM) in maternal blood did not differ among treatments. However, Zn concentration in colostrum and blood of calves increased linearly. The concentration of IgA and IgM in colostrum increased linearly with increasing Zn-Met supplementation, whereas no differences in immunoglobulins were observed in calf blood. In conclusion, Zn supplementation as Zn-Met at 40 of mg/kg of DM may improve antioxidant activity of dam and potentially increase passive immunity transfer in calves.

Effects of different dietary ratio of physically effective neutral detergent fiber and metabolizable glucose on rumen fermentation, blood metabolites and growth performance of 8 to 10-month-old heifers.

OBJECTIVE: The present study was undertaken to determine an optimal balance between the amount of physically effective neutral detergent fiber (peNDF) to metabolizable glucose (MG) on rumen fermentation, blood metabolites and growth performance of 8 to 10-month-old heifers. METHODS: A total of 15 healthy Holstein heifers weighing an average of 256 kg (8 month of age) were randomly assigned to three groups of five. Treatment diets consisted of the following three peNDF8.0/MG levels: 1.46 (Treatment A), 1.74 (Treatment B), and 2.08 (Treatment C). RESULTS: The results showed that the ratio of peNDF8.0/MG affected rumen fermentation, blood metabolites and growth performance of heifers. The average daily gain of heifers tended to decrease as the ratio of peNDF8.0/MG increased (p = 0.07). The concentrations of blood urea nitrogen, triglyceride, and cholesterol increased significantly (p<0.05), while the high-density lipoprotein concentration decreased (p<0.05). After feeding 2 h and 4 h, insulin concentration in Treatment A was greater than Treatment C (p<0.05). Propionate concentration had decreasing trend (p = 0.07); acetate to propionate ratio and non-glucogenic to glucogenic volatile fatty acid (NGR) increased significantly (p<0.05). In addition, the digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber decreased significantly (p<0.05). CONCLUSION: The present investigation indicated that dietary peNDF8.0/MG ratio can affect the growth and development, blood metabolites, rumen fermentation and apparent digestibility of heifers, and the optimal dietary peNDF8.0/MG ratio for 8 to 10-month-old heifers in the present study was 1.46.

Effects of Glucose and Starch on Lactate Production by Newly Isolated Streptococcus bovis S1 from Saanen Goats.

UNLABELLED: When ruminants are fed high-concentrate diets, Streptococcus bovis proliferates rapidly and produces lactate, potentially causing rumen acidosis. Understanding the regulatory mechanisms of the metabolism of this species might help in developing dietary strategies to alleviate rumen acidosis. S. bovis strain S1 was newly isolated from the ruminal fluid of Saanen dairy goats and then used to examine the effects of glucose and starch on bacterial metabolism and gene regulation of the organic acid-producing pathway in cultures at a pH of 6.5. Glucose or starch was added to the culture medium at 1 g/liter, 3 g/liter (close to a normal range in the rumen fluid), or 9 g/liter (excessive level). Lactate was the dominant acid produced during the fermentation, and levels increased with the amount of glucose or starch in a dose-dependent manner (P < 0.001). The production of formate and acetate in the fermentation media fluctuated slightly with the dose but accounted for small fractions of the total acids. The activities of lactate dehydrogenase (LDH) and α-amylase (α-AMY) increased with the starch dose (P < 0.05), but the α-AMY activity did not change with the glucose dose. The relative expression levels of the genes ldh, pfl (encoding pyruvate formate lyase), ccpA (encoding catabolite control protein A), and α-amy were higher at a dose of 9 g/liter than at 1 g/liter (P < 0.05). Expression levels of pfl and α-amy genes were higher at 3 g/liter than at 1 g/liter (P < 0.05). The fructose 1,6-diphosphate (FDP) concentration tended to increase with the glucose and starch concentrations. In addition, the S. bovis S1 isolate fermented glucose much faster than starch. We conclude that the quantities of glucose and soluble starch had a major effect on lactate production due to the transcriptional regulation of metabolic genes. IMPORTANCE: This work used a newly isolated S. bovis strain S1 from the rumen fluid of Saanen goats and examined the effects of glucose and soluble starch on organic acid patterns, enzyme activity, and expression of genes for in vitro fermentation. It was found that lactate was the dominant product from S. bovis strain S1, and the quantities of both glucose and starch in the medium were highly correlated with lactate production and with the corresponding changes in associated enzymes and genes. Therefore, manipulating the metabolic pathway of S. bovis to alter the dietary level of readily fermentable sugar and carbohydrates may be a strategy to alleviate rumen acidosis.

Arginine Relieves the Inflammatory Response and Enhances the Casein Expression in Bovine Mammary Epithelial Cells Induced by Lipopolysaccharide.

As one of functional active amino acids, L-arginine holds a key position in immunity. However, the mechanism that arginine modulates cow mammary inflammatory response in ruminant is unclear. Therefore, this study was conducted to investigate the effects of L-arginine on inflammatory response and casein expression after challenging the bovine mammary epithelial cells (BMECs) with lipopolysaccharide (LPS). The cells were divided into four groups, stimulated with or without LPS (10 µg/mL) and treated with or without arginine (100 µg/mL) for 12 h. The concentration of proinflammatory cytokines, inducible nitric oxide synthase (iNOS), mammalian target of rapamycin (mTOR), and Toll-like receptor 4 (TLR4) signaling pathways as well as the casein was determined. The results showed that arginine reduced the LPS-induced production like IL-1ß, IL-6, TNF-α, and iNOS. Though the expression of NF-κB was attenuated and the mTOR signaling pathway was upregulated, arginine had no effect on TLR4 expression. In addition, our results show that the content of ß-casein and the total casein were enhanced after arginine was supplemented in LPS-induced BMECs. In conclusion, arginine could relieve the inflammatory reaction induced by LPS and enhance the concentration of ß-casein and the total casein in bovine mammary epithelial cells.

Optimizing dietary rumen-degradable starch to rumen-degradable protein ratio improves lactation performance and nitrogen utilization efficiency in mid-lactating Holstein dairy cows.

The dietary rumen-degradable starch (RDS) to rumen-degradable protein (RDP) ratio, denoted as the RDS-to-RDP ratio (SPR), has been proven to enhance in vitro rumen fermentation. However, the effects of dietary SPR in vivo remain largely unexplored. This study was conducted to investigate the effect of dietary SPR on lactation performance, nutrient digestibility, rumen fermentation patterns, blood indicators, and nitrogen (N) partitioning in mid-lactating Holstein cows. Seventy-two Holstein dairy cows were randomly assigned to three groups (24 head/group), balanced for (mean ± standard deviation) days in milk (116 ± 21.5), parity (2.1 ± 0.8), milk production (42 ± 2.1 kg/d), and body weight (705 ± 52.5 kg). The cows were fed diets with low (2.1, control), medium (2.3), or high (2.5) SPR, formulated to be isoenergetic, isonitrogenous, and iso-starch. The study consisted of a one-week adaptation phase followed by an eight-week experimental period. The results indicated that the high SPR group had a lower dry matter intake compared to the other groups (p < 0.05). A quadratic increase in milk yield and feed efficiency was observed with increasing dietary SPR (p < 0.05), peaking in the medium SPR group. The medium SPR group exhibited a lower milk somatic cell count and a higher blood total antioxidant capacity compared to other groups (p < 0.05). With increasing dietary SPR, there was a quadratic improvement (p < 0.05) in the total tract apparent digestibility of crude protein, ether extract, starch, neutral detergent fiber, and acid detergent fiber. Although no treatment effect was observed in rumen pH, the rumen total volatile fatty acids concentration and microbial crude protein synthesis increased quadratically (p < 0.05) as dietary SPR increased. The molar proportion of propionate linearly increased (p = 0.01), while branched-chain volatile fatty acids linearly decreased (p = 0.01) with increasing dietary SPR. The low SPR group (control) exhibited higher concentration of milk urea N, rumen ammonia N, and blood urea N than other groups (p < 0.05). Despite a linear decrease (p < 0.05) in the proportion of urinary N to N intake, increasing dietary SPR led to a quadratic increase (p = 0.01) in N utilization efficiency and a quadratic decrease (p < 0.05) in the proportion of fecal N to N intake. In conclusion, optimizing dietary SPR has the potential to enhance lactation performance and N utilization efficiency. Based on our findings, a medium dietary SPR (with SPR = 2.3) is recommended for mid-lactating Holstein dairy cows. Nevertheless, further research on rumen microbial composition and metabolites is warranted to elucidate the underlying mechanisms of the observed effects.

Early microbial intervention reshapes phenotypes of newborn Bos taurus through metabolic regulations.

BACKGROUND: The rumen of neonatal calves has limited functionality, and establishing intestinal microbiota may play a crucial role in their health and performance. Thus, we aim to explore the temporal colonization of the gut microbiome and the benefits of early microbial transplantation (MT) in newborn calves. RESULTS: We followed 36 newborn calves for 2 months and found that the composition and ecological interactions of their gut microbiomes likely reached maturity 1 month after birth. Temporal changes in the gut microbiome of newborn calves are widely associated with changes in their physiological statuses, such as growth and fiber digestion. Importantly, we observed that MT reshapes the gut microbiome of newborns by altering the abundance and interaction of Bacteroides species, as well as amino acid pathways, such as arginine biosynthesis. Two-year follow-up of those calves further showed that MT improves their later milk production. Notably, MT improves fiber digestion and antioxidant capacity of newborns while reducing diarrhea. MT also contributes to significant changes in the metabolomic landscape, and with putative causal mediation analysis, we suggest that altered gut microbial composition in newborns may influence physiological status through microbial-derived metabolites. CONCLUSIONS: Our study provides a metagenomic and metabolomic atlas of the temporal development of the gut microbiome in newborn calves. MT can alter the gut microbiome of newborns, leading to improved physiological status and later milk production. The data may help develop strategies to manipulate the gut microbiota during early life, which may be relevant to the health and production of newborn calves.

Temporal colonization and metabolic regulation of the gut microbiome in neonatal oxen at single nucleotide resolution.

The colonization of microbes in the gut is key to establishing a healthy host-microbiome symbiosis for newborns. We longitudinally profiled the gut microbiome in a model consisting of 36 neonatal oxen from birth up to 2 months postpartum and carried out microbial transplantation to reshape their gut microbiome. Genomic reconstruction of deeply sequenced fecal samples resulted in a total of 3931 metagenomic-assembled genomes from 472 representative species, of which 184 were identified as new species when compared with existing databases of oxen. Single nucleotide level metagenomic profiling shows a rapid influx of microbes after birth, followed by dynamic shifts during the first few weeks of life. Microbial transplantation was found to reshape the genetic makeup of 33 metagenomic-assembled genomes (FDR < 0.05), mainly from Prevotella and Bacteroides species. We further linked over 20 million microbial single nucleotide variations to 736 plasma metabolites, which enabled us to characterize 24 study-wide significant associations (P < 4.4 × 10-9) that identify the potential microbial genetic regulation of host immune and neuro-related metabolites, including glutathione and L-dopa. Our integration analyses further revealed that microbial genetic variations may influence the health status and growth performance by modulating metabolites via structural regulation of their encoded proteins. For instance, we found that the albumin levels and total antioxidant capacity were correlated with L-dopa, which was determined by single nucleotide variations via structural regulations of metabolic enzymes. The current results indicate that temporal colonization and transplantation-driven strain replacement are crucial for newborn gut development, offering insights for enhancing newborn health and growth.

De novo transcriptome assembly database for 100 tissues from each of seven species of domestic herbivore.

Domesticated herbivores are an important agricultural resource that play a critical role in global food security, particularly as they can adapt to varied environments, including marginal lands. An understanding of the molecular basis of their biology would contribute to better management and sustainable production. Thus, we conducted transcriptome sequencing of 100 to 105 tissues from two females of each of seven species of herbivore (cattle, sheep, goats, sika deer, horses, donkeys, and rabbits) including two breeds of sheep. The quality of raw and trimmed reads was assessed in terms of base quality, GC content, duplication sequence rate, overrepresented k-mers, and quality score distribution with FastQC. The high-quality filtered RNA-seq raw reads were deposited in a public database which provides approximately 54 billion high-quality paired-end sequencing reads in total, with an average mapping rate of ~93.92%. Transcriptome databases represent valuable resources that can be used to study patterns of gene expression, and pathways that are related to key biological processes, including important economic traits in herbivores.

Rumen-Protected Lysine and Methionine Supplementation Reduced Protein Requirement of Holstein Bulls by Altering Nitrogen Metabolism in Liver.

The aim of this study was to investigate the effect of low-protein diets supplemented with rumen-protected lysine (RPLys) and methionine (RPMet) on growth performance, rumen fermentation, blood biochemical parameters, nitrogen metabolism, and gene expression related to N metabolism in the liver of Holstein bulls. Thirty-six healthy and disease-free Holstein bulls with a similar body weight (BW) (424 ± 15 kg, 13 months old) were selected. According to their BW, they were randomly divided into three groups with 12 bulls in each group in a completely randomized design. The control group (D1) was fed with a high-protein basal diet (CP13%), while bulls in two low-protein groups were supplied a diet with 11% crude protein and RPLys 34 g/d·head + RPMet 2 g/d·head (low protein with low RPAA, T2) or RPLys 55 g/d·head + RPMet 9 g/d·head (low protein with high RPAA, T3). At the end of the experiment, the feces and urine of dairy bulls were collected for three consecutive days. Blood and rumen fluid were collected before morning feeding, and liver samples were collected after slaughtering. The results showed that the average daily gain (ADG) of bulls in the T3 group was higher than those in D1 (p < 0.05). Compared with D1, a significantly higher nitrogen utilization rate (p < 0.05) and serum IGF-1 content (p < 0.05) were observed in both T2 and T3 groups; however, blood urea nitrogen (BUN) content was significantly lower in the T2 and T3 groups (p < 0.05). The content of acetic acid in the rumen of the T3 group was significantly higher than that of the D1 group. No significant differences were observed among the different groups (p > 0.05) in relation to the alpha diversity. Compared with D1, the relative abundance of Christensenellaceae_R-7_group in T3 was higher (p < 0.05), while that of Prevotellaceae _YAB2003_group and Succinivibrio were lower (p < 0.05). Compared with D1 and T2 group, the T3 group showed an expression of messenger ribonucleic acid (mRNA) that is associated with (CPS-1, ASS1, OTC, ARG) and (N-AGS, S6K1, eIF4B, mTORC1) in liver; moreover, the T3 group was significantly enhanced (p < 0.05). Overall, our results indicated that low dietary protein (11%) levels added with RPAA (RPLys 55 g/d +RPMet 9 g/d) can benefit the growth performance of Holstein bulls by reducing nitrogen excretion and enhancing nitrogen efficiency in the liver.

Black Lycium barbarum polysaccharide attenuates LPS-induced intestine damage via regulation gut microbiota.

Lycium barbarums are traditionally used as a homology of medicinal plants in China with a potent role in metabolism and immunomodulation. The current study was performed to explore the attenuation effect and microbiota regulation of Lycium barbarum polysaccharide (BLBP) on lipopolysaccharide (LPS)-induced intestine damage in mice. A total of 70 mice were randomly divided into five groups; negative control (GA), LPS (GB), both treated with an equal volume of normal saline, and BLBP treatment groups GC (100 mg/kg), GD (200 mg/kg), and GE (400 mg/kg) via gavage for 19 days. On Day 19, mice in groups GB, GC, GD, and GE were treated with 10 mg/kg LPS for 24 h and euthanized to collect intestine samples for pathological examination and microbiota sequencing. The results showed a non-significant difference in body weight gain among the five mouse groups; however, mice in the GC and GE groups showed decreased weight gain. An H&E examination revealed that the integrity of intestinal villi was destroyed by LPS, while BLBP supplement alleviated intestinal damage with an increase in villus height and a decrease in crypt depth. A total of over 59,000, 40,000, 50,000, 45,000, and 55,000 raw sequences were found in groups GA, GB, GC, GD, and GE, respectively. LPS challenge decreased alpha diversity indexes significantly (p < 0.05), while a non-significant difference was found between different BLBP treatment groups and the GA group. A total of 8 phyla and 13 genera were found among five mouse groups, and BLBP partly restored the bacterial abundance in mice. LPS changed 282 metabolic pathways in KEGG L2, 77 metabolic pathways in KEGG L3, and 205 metabolic pathways in MetaCyc, respectively. The BLBP-supplemented groups, especially GE, showed reverse effects on those metabolic pathways. The current study revealed that BLBP can effectively decrease intestinal damage through the regulation of intestinal microbiota, which may provide new insights for the prevention of intestinal disease using food and medicine homologous of Lycium ruthenicum.

Microbiome-Metabolome Responses in Ruminal Content and Feces of Lactating Dairy Cows With N-Carbamylglutamate Supplementation Under Heat Stress.

The objective of the present study was to investigate the effects of N-carbamylglutamate (NCG) supplementation on metabolic profile and microbiota in ruminal content and feces of lactating dairy cows under heat stress (HS). Forty-eight lactating Holstein cows (154 ± 13.6 days in milk) were assigned randomly to four treatments (n = 12), to receive 0, 15, 20, or 25 g/day of commercial NCG (proportion: 97.7%) for the period of 60 days. The recorded ambient temperature-humidity index (THI) suggested that the cows were exposed to HS for almost the entire experimental period (average THI: 80.6). Samples of ruminal content and feces were collected at the end of the trial (day 60) to determine the biological effects of NCG supplementation on metabolome and microbiota using mass spectrometry-based metabolomics and 16S rRNA gene sequencing techniques, respectively. Results showed that NCG supplementation enhanced the levels of ruminal microbial protein, total volatile fatty acids (VFAs), and the molar proportion of propionate in the rumen, but lowered the ruminal pH, ammonia nitrogen (NH3-N), and the ratio of acetate to propionate. NCG at doses of 20 and 25 g/day reduced the community richness and diversity of ruminal microbiota with the decrease of Shannon and Simpson diversity. Compositions of ruminal and fecal microbiotas were altered by NCG, and the PICRUSt results revealed that metabolic pathways of the bacteria, such as amino acid metabolism, energy metabolism, and pyruvate metabolism, were enriched in NCG groups. Distinct changes in the metabolomic profile of ruminal fluid were observed between the control and NCG groups. Changes of 26 metabolites mainly involved in arginine metabolism, glutamate metabolism, and nitrogen metabolism were observed associated with NCG supplementation. These results provided new insights into the effects of NCG on metabolomic profile and microbiota in ruminal content and feces, and the optimal dose of NCG supplemented to dairy cows was 20 g/hd/day, which contributed to understanding the effects of NCG on HS in lactating dairy cows.

Nutritional Value, Fermentation Characteristics and In Vitro Degradability of Whole Wheat Hay Harvested at Three Stages of Maturity.

The nutritional value of whole crop wheat hay (WCWH) harvested at different maturation stages are different, and its feeding effects on dairy cows have not been thoroughly evaluated. In this study, the in vitro digestibility of whole wheat (Nongda 22) hay harvested during the flowering, late milk and dough stages were evaluated using batch culture technique. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of whole wheat hay decreased by 35.5% and 40.4%, respectively, whereas the non-fibrous carbohydrates (NFC) content increased by 50.3% in WCWH harvested during the dough stage as compared to the flowering stage (p < 0.01). The pH of the fermentation liquid and acetate to propionate ratio was greatest in the wheat harvested during the flowering stage and lowest during the dough stage (p = 0.03), whereas the volatile fatty acid (VFA) concentration was greatest during the dough stage and lowest during the flowering stage (p < 0.01). The dry matter loss (DML) was 9.6% and 6.2% greater (p < 0.01) during the late milk stage than in the flowering or dough stages, and the NDF loss (NDFL; p = 0.01) and ADF loss (ADFL; p < 0.01) was greater in both the flowering and late milk stages. In conclusion, though the content of NDF was lower in the dough stage, and the starch to NFC ratio was greater, we determined that the optimal harvest stage should be the late milk stage due to the greater dry matter digestibility, the relatively greater NFC content and the shorter planting days.

Effect of Dietary Rumen-Degradable Starch to Rumen-Degradable Protein Ratio on In Vitro Rumen Fermentation Characteristics and Microbial Protein Synthesis.

The objective of this study was to investigate the effects of dietary rumen-degradable starch (RDS, g/kg of DM) to rumen-degradable protein (RDP, g/kg of DM) ratios (SPR) on in vitro rumen fermentation characteristics and microbial protein synthesis (MCPS). Treatments were eight diets with SPR of 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and 2.6 and were formulated to be isoenergetic, isonitrogenous, and isostarch. Substrates were anaerobically incubated in sealed culture vials (100 mL) for 6, 24 or 48 h. Three incubation runs were conducted within two consecutive weeks. With the increase of the dietary SPR, the gas production (GP), in vitro dry matter disappearance (IVDMD) and concentration of MCPS and total volatile fatty acids (TVFA) linearly increased after 6 h of incubation (p ≤ 0.01), whereas they quadratically increased and peaked at the SPR of 2.3 after 24 and 48 h of incubation (p < 0.05). In response to dietary SPR increasing, the in vitro neutral detergent fiber disappearance (IVNDFD) quadratically increased (p < 0.01), and the ammonia nitrogen (NH3-N) concentration linearly decreased (p < 0.01) after 6, 24 and 48 h of incubation. Based on the presented results, an SPR of 2.3 is recommended for formulating a diet due to its greatest IVDMD, IVNDFD, GP, TVFA and MCPS. However, as the results obtained are strictly dependent on the in vitro conditions, further in vivo studies are needed to verify our findings.

Selenium Plays an Anti-Inflammatory Role by Regulation NLRP3 Inflammasome in Staphylococcus aureus-Infected Mouse Mammary Gland.

Selenium is an essential micronutrient that plays an important role in immunity. However, the mechanism that Selenium modulates mastitis is not fully clear. In this experiment, we investigated whether selenium can inhibit the activation of the NLRP3 inflammasome in a mouse model of Staphylococcus aureus-induced mastitis. Eighty BALB/c female mice were fed with experimental Selenium deficiency basal diet for 2 weeks to achieve the purpose of selenium consumption until pregnancy. Pregnant mice were randomly divided into four groups (control group; selenium supplement group; Staphylococcus aureus infection group and Staphylococcus aureus infection after selenium supplement group). Twenty-four hours after challenging, all mice were euthanized and mammary tissue samples were aseptically collected. Through pathological staining, western blot analysis, real-time fluorescence quantitative polymerase chain reaction analysis, and enzyme-linked immunosorbent assay, the regulation effect of Selenium on NLRP3 inflammasome was detected. The result showed that compared with the control group, selenium significantly inhibited the expression of NLRP3, ASC, Caspase-1, Caspase-1 p20, and Pro-IL-1ß (p < 0.01). Meanwhile the mRNA expression and release of IL-1ß was suppressed in the treatment group compared with Staphylococcus aureus infection group (p < 0.01). Therefore, these results suggest that dietary selenium can attenuate Staphylococcus aureus mastitis by inhibition of the NLRP3 inflammasome.

Contents and yields of copper, iron, manganese and zinc would be affected by lucerne age and cut.

BACKGROUND: Lucerne is a perennial legume forage, which can produce multiple cuts in 1 year. Microelements play fundamental roles in the function, maintenance and adaptation to the environment for lucerne growth. However, the role of the accumulation of copper (Cu), iron (Fe), manganese (Mn) and Zinc (Zn), which vary with lucerne ages or cuts, has not been previously determined. Therefore, a hypothesis on the Cu, Fe, Mn and Zn in lucerne varying with age and cut was tested. METHODS: A total of 11, 8, 5, 4 and 1 year old lucerne (Medicago sativa Longdong) were selected as the material (until 2012 year), and samples were taken as three cuts at the cutting periods (early flowering stage) in 2012. Then, the contents and yields of Cu, Fe, Mn and Zn in lucerne were measured and calculated. RESULTS: The highest contents of Cu, Fe, Mn and Zn in lucerne were found in the 1 year old among the five ages, at the 3rd cut compared to the other two cuts, and in the leaf among the three organs. The highest yields of Cu, Fe, Mn and Zn were found in the older ages (11 and 8 years old), at the 3rd cut, and in the root among the three organs. The most positive correlations were found between contents, yields and biomass. CONCLUSIONS: The hypothesis was supported by the results. And the contents and yields of lucerne Cu, Fe, Mn and Zn were affected by the age, cut and organ. Furthermore, the yields of lucerne Cu, Fe, Mn and Zn were determined by their contents and lucerne biomass.

Vitamin E and selenium supplementation synergistically alleviate the injury induced by hydrogen peroxide in bovine granulosa cells.

Dairy cows are susceptible to reproductive disorders, which are thought to be associated with oxidative stress. In the study, we investigated the effects of vitamin E (VE) and selenium (Se) on the proliferation, apoptosis, and steroidogenesis in bovine ovarian granulosa cells under hydrogen peroxide (H2O2) - induced oxidative stress and elaborated the underlying mechanisms. Our results showed that VE or Se could stimulate the granulosa cell proliferation, possibly due to up-regulating the expression of CCND1 and decreasing the P21 levels under oxidative stress. VE or Se treatment also increased the secretion of estradiol (E2) and progesterone (P4), which could be owing to improving the expression of genes associated with steroidogenesis (StAR, HSD3ß1, and CYP19A1) expression. VE or Se treatment down-regulated the apoptosis-related genes (BAX, CASP3) expression and decreased cell apoptosis. Furthermore, VE or Se treatment inhibited reactive oxidative species (ROS) and malondialdehyde (MDA) generation, increased total antioxidant capacity (T-AOC), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). Additionally, VE or Se treatment also alleviated the endoplasmic reticulum stress, activated the nuclear factor erythroid 2-related factor 2 (NRF2), and up-regulated the expression of its downstream genes, including NQO1, HO-1, GCLM, GCLC. More importantly, compared with either VE or Se treatment alone, their combined treatment showed a better protective effect against oxidative damage. Overall, our results indicated that VE and Se synergistically stimulated the granulosa cell proliferation and steroidogenesis, decreased cell apoptosis, mitigated the endoplasmic reticulum stress by activating the NRF2 signal pathway.

Feed nutritional value of brewers' spent grain residue resulting from protease aided protein removal.

BACKGROUND: This study was conducted to evaluate the feed nutritional value of brewers' spent grain (BSG) residue resulting from protease aided protein removal. The nutritional value was measured as nutrient content, gas production, nutrient digestibility and fermentation characteristics in batch culture. RESULTS: Protein extraction process decreased content of crude protein but concentrated the neutral detergent fibre (NDF) and ferulic acid in BSG residue. The changes in the chemical composition of BSG residue varied with enzyme and enzyme dosage. Digestibility of dry matter (DMD) and NDF of residue differed among proteases. Increasing alcalase dosage linearly decreased DMD, whereas, the DMD linearly increased as everlase or flavourzyme dosage increased. Compared with BSG, the DMD, gas production and fermentation acid concentration of BSG residues were lower, whereas NDF digestibility was higher. CONCLUSIONS: The substantially increased NDF content and improved in vitro NDF digestibility due to protease hydrolysis suggest that BSG residue can be potentially exploited as a viable fibre source for ruminant feeding.