Effects of maternal high-fat diet on fetal growth, placental nutrient transporters and circular RNA expression profiles.

Epidemiological and experimental studies suggest that there is a strong correlation between maternal high-fat diet and fetal-placental development. The current study aims to investigate the effects of maternal high-fat diet on fetal growth, placental nutrient transporters and circular RNA expression profiles in a mouse model. Forty C57BL/6 female mice were randomly assigned to two groups, fed either a control (10% fat for energy) diet (CON) or a high-fat (60% fat for energy) diet (HFD) for 4 weeks before mating and throughout pregnancy, and were killed on day 19.5 of pregnancy. The serum glucose, total cholesterol and low-density lipoprotein, the glucolipid metabolism-related hormones, and the insulin resistance index were significantly increased. High-throughput sequencing showed that differentially expressed circRNAs (DE circRNAs) in the placenta can regulate various biological processes, cellular components, and molecular functions through various energy metabolism pathways, and mmu-let-7g-5p was found to target and bind to multiple DE circRNAs. In addition, this study also predicted that various circRNAs with protein coding functions can regulate maternal placental nutrient transport. In general, the ceRNA (circRNAs-miRNAs-mRNAs) regulatory network of maternal placental nutrient transport constructed in this study is of great significance for further understanding the effect of maternal nutrition on fetal growth in the future.

Effects of Serotonin on Cell Viability, Permeability of Bovine Mammary Gland Epithelial Cells and Their Transcriptome Analysis.

Serotonin (5-HT) has been reported to play an important role in mammary gland involution that is defined as the process through which the gland returns to a nonlactating state. However, the overall picture of the regulatory mechanisms of 5-HT and the effects of serotonylation on mammary gland involution still need to be further investigated. The current study aimed to investigate the effects of 5-HT on global gene expression profiles of bovine mammary epithelial cells (MAC-T) and to preliminarily examine whether the serotonylation involved in the mammary gland involution by using Monodansylcadaverine (MDC), a competitive inhibitor of transglutaminase 2. Results showed that a high concentration of 5-HT decreased viability and transepithelial electrical resistance (TEER) in MAC-T cells. Transcriptome analysis indicated that 2477 genes were differentially expressed in MAC-T cells treated with 200 µg/mL of 5-HT compared with the control group, and the Notch, p53, and PI3K-Akt signaling pathways were enriched. MDC influenced 5-HT-induced MAC-T cell death, fatty acid synthesis, and the formation and disruption of tight junctions. Overall, a high concentration of 5-HT is able to accelerate mammary gland involution, which may be regulated through the Notch, p53, and PI3K-Akt signaling pathways. Serotonylation is involved in bovine mammary gland involution.

Effect of Heat Stress on Bovine Mammary Cellular Metabolites and Gene Transcription Related to Amino Acid Metabolism, Amino Acid Transportation and Mammalian Target of Rapamycin (mTOR) Signaling.

Heat stress (HS) is one of the most serious factors to negatively affect the lactation performance of dairy cows. Bovine mammary epithelial cells are important for lactation. It was demonstrated that HS decreases the lactation performance of dairy cows, partly through altering gene expression within bovine mammary epithelial tissue. However, the cellular metabolism mechanisms under HS remains largely unknown. The objective of this study was to determine whether HS induced changes in intracellular metabolites and gene transcription related to amino acid metabolism, amino acid transportation and the mTOR signaling pathway. Immortalized bovine mammary epithelial cell lines (MAC-T cells, n = 5 replicates/treatment) were incubated for 12 h at 37 °C (Control group) and 42 °C (HS group). Relative to the control group, HS led to a greater mRNA expression of heat shock protein genes HSF1, HSPB8, HSPA5, HSP90AB1 and HSPA1A. Compared with the control group, metabolomics using liquid chromatography tandem-mass spectrometry identified 417 differential metabolites with p < 0.05 and a variable importance in projection (VIP) score >1.0 in the HS group. HS resulted in significant changes to the intracellular amino acid metabolism of glutathione, phenylalanine, tyrosine, tryptophan, valine, leucine, isoleucine, arginine, proline, cysteine, methionine, alanine, aspartate and glutamate. HS led to a greater mRNA expression of the amino acid transporter genes SLC43A1, SLC38A9, SLC36A1, and SLC3A2 but a lower mRNA expression of SLC7A5 and SLC38A2. Additionally, HS influenced the expression of genes associated with the mTOR signaling pathway and significantly upregulated the mRNA expression of mTOR, AKT, RHEB, eIF4E and eEF2K but decreased the mRNA expression of TSC1, TSC2 and eEF2 relative to the control group. Compared with the control group, HS also led to greater mRNA expression of the CSN1S2 gene. Overall, our study indicates that bovine mammary epithelial cells may have the ability to resist HS damage and continue milk protein synthesis partly through enhanced intracellular amino acid absorption and metabolism and by activating the mTOR signaling pathway during HS.

Sodium Butyrate More Effectively Mitigates the Negative Effects of High-Concentrate Diet in Dairy Cows than Sodium ß-Hydroxybutyrate via Reducing Free Bacterial Cell Wall Components in Rumen Fluid and Plasma.

The present study was aimed at investigating the effects of sodium butyrate and sodium ß-hydroxybutyrate on lactation and health of dairy cows fed a high-concentrate (HC) diet. Eighty mid-lactation dairy cows with an average milk yield of 33.75 ± 5.22 kg/d were randomly allocated to four groups (n = 20 per group) and were fed either a low-concentrate (LC) diet, a HC diet, the HC diet with 1% sodium butyrate (HCSB), or the HC diet with 1% sodium ß-hydroxybutyrate (HCHB). The feeding trial lasted for 7 weeks, with a 2-week adaptation period and a 5-week measurement period, and the trial started from 96 ± 13 d in milk. Sodium butyrate supplementation delayed the decline in milk production and improved milk synthesis efficiency and milk fat content. Additionally, it decreased the proinflammatory cytokines and acute phase proteins (APPs) in plasma, the leucocytes in blood, the somatic cell count (SCC) in milk, and the gene expression of pattern recognition receptors (PRRs) and proinflammatory cytokines in the mammary gland, due to decreasing the contents of bacterial cell wall components (lipopolysaccharide, LPS; peptidoglycan, PGN; and lipoteichoic acid, LTA) in the rumen and plasma, compared with the HC diet. Sodium ß-hydroxybutyrate supplementation also improved milk yield, milk synthesis efficiency and milk fat content and partially reduced the adverse effects caused by the HC diet, but it had no effect on decreasing bacterial cell wall components in the rumen and plasma, compared with the HC diet. Collectively, both sodium butyrate and sodium ß-hydroxybutyrate mitigated the negative effects of HC diet on lactation and health of dairy cows, with sodium butyrate being more effective than sodium ß-hydroxybutyrate.

A solid-phase microextraction fiber coating based on magnetic covalent organic framework for highly efficient extraction of triclosan and methyltriclosan in environmental water and human urine samples.

Herein, we synthesized a kind of magnetic covalent organic framework nanohybrids (NiFe2O4@COF), and integrated it with polydimethyl siloxane and silicone rubber curing agent for solid phase microextraction (SPME) fiber coating. The fiber coating demonstrated a porous and uniform surface with the BET specific surface of 169.7 m2 g-1. As for seven environmental analytes, the NiFe2O4@COF-based SPME fiber coating gave the higher extraction recoveries for triclosan (TCS) and methyltriclosn (MTCS) than those of fenpropathrin, bifenthrin, permethrin, fenvalerate and deltamethrin. Several operational parameters were rigorously optimized, such as extraction temperature, extraction time, thermal desorption time, solution pH and salt effect. Combined with the GC-ECD detection, the newly developed microextraction method supplied the wide linear range of 0.1-1000 µg L-1 with the correlation coefficients of > 0.9995. The limits of detection (LODs) and limits of quantitation (LOQs) reached as low as 1-7 ng L-1 and 3.3-23 ng L-1, respectively. The intra-day and inter-day precisions in six replicates (n = 6 ) were < 3.55% and < 5.06%, respectively, and the fiber-to-fiber reproducibility (n = 3) was < 7.64%. To evaluate its feasibility in real samples, the fortified recoveries for TCS and MTCS, at low (0.2 µg L-1), middle (2.0 µg L-1) and high (20.0 µg L-1) levels, varied between 81.9% and 119.1% in tap, river and barreled waters as well as male, female and children urine samples. Especially, it is worth mentioning that the NiFe2O4@COF-based SPME coating fiber can be recycled for at least 150 times with nearly unchanged extraction efficiency. Moreover, the extraction recoveries by the as-fabricated fiber coating were much higher than those by three commercial fibers (PDMS, PDMS/DVB and PDMS/DVB/CAR). Overall, the NiFe2O4@COF-based SPME is a convenient, sensitive, efficient and "green" pretreatment method, thereby possessing important application prospects in trace monitoring of TCS-like pollutants in complex liquid matrices.

Functional Role of circRNAs in the Regulation of Fetal Development, Muscle Development, and Lactation in Livestock.

circRNAs are a class of endogenous noncoding RNA molecules with closed loop structures. They are mainly responsible for regulating gene expression in eukaryotic cells. With the emergence of high-throughput RNA sequencing (RNA-Seq) and new types of bioinformatics tools, thousands of circRNAs have been discovered, making circRNA one of the research hotspots. Recent studies have shown that circRNAs play an important regulatory role in the growth, reproduction, and formation of livestock products. They can not only regulate mammalian fetal growth and development but also have important regulatory effects on livestock muscle development and lactation. In this review, we briefly introduce the putative biogenic pathways and regulatory functions of circRNA and highlight our understanding of circRNA and its latest advances in fetal development, muscle development, and lactation biogenesis as well as expression in livestock. This review will provide a theoretical basis for the research and development of related industries.

Dandelion Extract Alleviated Lipopolysaccharide-Induced Oxidative Stress through the Nrf2 Pathway in Bovine Mammary Epithelial Cells.

In practical dairy production, cows are frequently subjected to inflammatory diseases, such as high-grain diet-induced subacute ruminal acidosis (SARA) as well as mastitis and metritis. Under the circumstances, lipopolysaccharide (LPS) induces oxidative stress within the cow and in the mammary epithelial cells. It has implications in practical production to alleviate oxidative stress and to optimize the lactational function of the mammary epithelial cells. This study thus aimed to investigate the antioxidative effects of dandelion aqueous extract (DAE) on LPS-induced oxidative stress and the mechanism of DAE as an antioxidant to alleviate oxidative stress through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the bovine mammary epithelial cell line MAC-T cells. The cells were cultured for 48 h in six treatments including control (without LPS and DAE), LPS (100 ng/mL), DAE10 (100 ng/mL LPS and 10 µg/mL DAE), DAE50 (100 ng/mL LPS and 50 µg/mL DAE), DAE100 (100 ng/mL LPS and 100 µg/mL DAE), and DAE200 (100 ng/mL LPS and 200 µg/mL DAE), respectively. The results showed that cell viability was reduced by LPS, and the adverse effect of LPS was suppressed with the supplementation of DAE. Lipopolysaccharide-induced oxidative stress through enhancing reactive oxygen species (ROS) production, resulted in increases in oxidative damage marker concentrations, while 10 and 50 µg/mL DAE alleviated the LPS-induced oxidative stress via scavenging cellular ROS and improving antioxidant enzyme activity. The upregulation of antioxidative gene expression in DAE treatments was promoted through activating the Nrf2 signaling pathway, with DAE at a concentration of 50 µg/mL exhibiting the highest effect. Overall, DAE acted as an effective antioxidant to inhibit LPS-induced oxidative stress and as a potential inducer of the Nrf2 signaling pathway.

Effects of Peptidoglycan, Lipoteichoic Acid and Lipopolysaccharide on Inflammation, Proliferation and Milk Fat Synthesis in Bovine Mammary Epithelial Cells.

The mammary gland of the cow is particularly susceptible to infections of a wide range of pathogenic bacteria, including both Gram-positive and Gram-negative bacteria. The endotoxins of these pathogenic bacteria include peptidoglycan (PGN), lipoteichoic acid (LTA) and lipopolysaccharide (LPS), and they are the pathogen-associated molecular patterns (PAMPs) to induce mastitis. LPS can directly inhibit proliferation and milk fat synthesis of bovine mammary epithelial cells (BMECs) while inducing mastitis, but it is unclear whether PGN and LTA also have such effects. Furthermore, since the three PAMPs usually appear simultaneously in the udder of cows with mastitis, their synergistic effects on proliferation and milk fat synthesis of BMECs are worth investigating. The immortalized BMECs (MAC-T cells) were stimulated for 24 h using various concentrations of PGN, LTA and LPS, respectively, to determine the doses that could effectively cause inflammatory responses. Next, the cells were stimulated for 24 h with no endotoxins (CON), PGN, LTA, LPS, PGN + LTA, and PGN + LTA + LPS, respectively, with the predetermined doses to analyze their effects on proliferation and milk fat synthesis of BMECs. PGN, LTA and LPS successfully induced inflammatory responses of BMECs with doses of 30, 30 and 0.1 µg/mL, respectively. Although the proliferation of BMECs was significantly inhibited in the following order: LTA < PGN + LTA < PGN + LTA + LPS, there was no change in cell morphology and cell death. LTA significantly promoted the expression of fatty acid synthesis-related genes but did not change the content of intracellular triglyceride (TG), compared with the CON group. The mRNA expression of fatty acid synthesis-related genes in the LPS group was the lowest among all the groups. Meanwhile, LPS significantly decreased the content of intracellular non-esterified fatty acids (NEFAs) and TG, compared with the CON group. PGN had no effects on milk fat synthesis. Co-stimulation with PGN, LTA and LPS significantly increased the expression of fat acid synthesis-related genes and the intracellular NEFAs, but decreased intracellular TG, compared with sole LPS stimulation. Collectively, PGN, LTA and LPS showed an additive effect on inhibiting proliferation of BMECs. The promoting role of LTA in fatty acid synthesis might offset the negative effects of LPS in this regard, but co-stimulation with PGN, LTA and LPS significantly decreased intracellular TG content.

The Synergism of PGN, LTA and LPS in Inducing Transcriptome Changes, Inflammatory Responses and a Decrease in Lactation as Well as the Associated Epigenetic Mechanisms in Bovine Mammary Epithelial Cells.

Mastitis is usually caused by a variety of pathogenic bacteria that include both Gram-positive and Gram-negative bacteria. Lipopolysaccharide (LPS) is the pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria, and peptidoglycan (PGN) and lipoteichoic acid (LTA) are those of Gram-positive bacteria. The effects of LPS, PGN and/or LTA on inflammatory response and lactation in bovine mammary epithelial cells (BMECs) are well studied, but the epigenetic mechanisms of their effects received less attention. Furthermore, since the three PAMPs are often simultaneously present in the udder of cows with mastitis, it has implications in practice to study their additive effects. The results show that co-stimulation of bovine mammary epithelial cells with PGN, LTA, and LPS induced a higher number of differentially expressed genes (DEGs) and greater expressions of inflammatory factors including interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor-α (TNF-α), chemokine (C-X-C motif) ligand (CXCL)1, and CXCL6. In addition, co-stimulation further increased DNA hypomethylation compared with sole LPS stimulation. Co-stimulation greatly decreased casein expression but did not further decrease histone acetylation levels and affect the activity of histone acetyltransferase (HAT) and histone deacetylase (HDAC), compared with sole LPS stimulation. Collectively, this study demonstrated that PGN, LTA, and LPS had an additive effect on inducing transcriptome changes and inflammatory responses in BMECs, probably through inducing a greater decrease in DNA methylation. Co-stimulation with PGN, LTA, and LPS decreased casein expression to a greater degree, but it might not be linked to histone acetylation and HAT and HDAC activity.

PGN and LTA from Staphylococcus aureus Induced Inflammation and Decreased Lactation through Regulating DNA Methylation and Histone H3 Acetylation in Bovine Mammary Epithelial Cells.

Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common pathogens of mastitis, and S. aureus generally causes subclinical mastitis which is more persistent and resistant to treatment. Peptidoglycan (PGN) and lipoteichoic acid (LTA) are cell wall components of S. aureus. Although the roles of PGN and LTA in causing inflammation are well studied, the epigenetic mechanisms of the effects of PGN and LTA on the inflammation and lactation remain poorly understood. This study characterized the gene expression profiling by RNA sequencing and investigated DNA methylation and histone acetylation in relation to inflammation and lactation in the immortalized bovine mammary epithelial cell line (MAC-T). The cells were cultured for 24 h with neither PGN nor LTA (CON), PGN (30 µg/mL), LTA (30 µg/mL), and PGN (30 µg/mL) + LTA (30 µg/mL), respectively. The number of differentially expressed genes (DEGs) and the expression of proinflammatory factors including interleukin (IL)-1ß, IL-6, IL-8, chemokine (C-X-C motif) ligand (CXCL)1, and CXCL6 of the treatments increased in the following order: CON < PGN < LTA < PGN + LTA, and the DEGs mainly enriched on the cytokine-cytokine receptor interaction and chemokine signaling pathway. LTA and PGN + LTA induced hypomethylation of global DNA by suppressing DNA methyltransferase (DNMT) activity. PGN and LTA, alone or combined, decreased the mRNA expression of casein genes (CSN1S1, CSN2, and CSN3) and the expression of two caseins (CSN2 and CSN3), and reduced histone H3 acetylation by suppressing histone acetyltransferase (HAT) activity and promoting histone deacetylase (HDAC) activity. Collectively, this study revealed that PGN and LTA induced inflammation probably due to decreasing DNA methylation through regulating DNMT activity, and decreased lactation possibly through reducing histone H3 acetylation by regulating HAT and HDAC activity in bovine mammary epithelial cells.

Niacin nutrition and rumen-protected niacin supplementation in dairy cows: an updated review.

As the precursor to NAD+ and NADP+, niacin is important for catabolic and anabolic redox reactions. In addition, niacin is known for its anti-lipolytic action via a hydroxycarboxylic acid-2-receptor-dependent mechanism. The anti-lipolytic effects of traditional free niacin supplementation during transition periods had been studied extensively, but the reported effects are ambiguous. In the past decade, a series of studies were conducted to evaluate the effects of rumen-protected niacin (RPN) on production performance and metabolic status in early lactation and on heat stress in dairy cows. Feeding RPN seems more effective than free niacin regarding increasing circulating niacin concentration. The rebound of plasma NEFA was found after termination of niacin abomasal infusion. Feeding RPN or infusion of niacin via the abomasum could suppress lipolysis and reduce insulin resistance in early lactation. Additionally, RPN supplementation could possibly relieve heat stress through vasodilation during moderate to severe heat stress condition. However, these beneficial effects of niacin supplementation have not always been observed. The inconsistent results across studies may be related to dosages of niacin supplementation, rebound of plasma NEFA concentration, stage of lactation or severity of heat stress. Overall, the current review is to present updated information on niacin nutrition in dairy cows and the recommendations are given for future research.

Bacterial endotoxin decreased histone H3 acetylation of bovine mammary epithelial cells and the adverse effect was suppressed by sodium butyrate.

BACKGROUND: In practical production, dairy cows are frequently exposed to bacterial endotoxin (lipopolysaccharide, LPS) when they are subjected to high-concentrate diets, poor hygienic environments, as well as mastitis and metritis. Histone acetylation is an important epigenetic control of DNA transcription and a higher histone acetylation is associated with facilitated transcription. LPS might reduce histone acetylation in the mammary epithelial cells, resulting in lower transcription and mRNA expression of lactation-related genes. This study was conducted to investigate the effect of LPS on histone acetylation in bovine mammary epithelial cells and the efficacy of sodium butyrate (SB) in suppressing the endotoxin-induced adverse effect. Firstly, the bovine mammary epithelial cell line MAC-T cells were treated for 48 h with LPS at different doses of 0, 1, 10, 100, and 1000 endotoxin units (EU)/mL (1 EU = 0.1 ng), and the acetylation levels of histones H3 and H4 as well as the histone deacetylase (HDAC) activity were measured. Secondly, the MAC-T cells were treated for 48 h as follows: control, LPS (100 EU/mL), and LPS (100 EU/mL) plus SB (10 mmol/L), and the acetylation levels of histones H3 and H4 as well as milk gene mRNA expressions were determined. RESULTS: The results showed that HDAC activity increased linearly with increasing LPS doses (P < 0.01). The histone H3 acetylation levels were significantly reduced by LPS, while the histone H4 acetylation levels were not affected by LPS (P > 0.05). Sodium butyrate, an inhibitor of HDAC, effectively suppressed the endotoxin-induced decline of histone H3 acetylation (P < 0.05). As a result, SB significantly enhanced the mRNA expression of lactation-related genes (P < 0.05). CONCLUSIONS: The results suggest one of the adverse effects of LPS on the lactation of bovine mammary gland epithelial cells was due to decreasing histone H3 acetylation through increasing HDAC activity, whereas the endotoxin-induced adverse effects were effectively suppressed by SB.

Bacterial Lipopolysaccharide Induced Alterations of Genome-Wide DNA Methylation and Promoter Methylation of Lactation-Related Genes in Bovine Mammary Epithelial Cells.

Bacterial lipopolysaccharide (LPS) could result in poor lactation performance in dairy cows. High methylation of DNA is associated with gene repression. However, it is unclear whether LPS could suppress the expression of lactation-related genes by inducing DNA methylation. Therefore, the objective of this study was to investigate the impact of LPS on genome-wide DNA methylation, using methylated DNA immunoprecipitation with high-throughput sequencing (MeDIP-seq) and on the promoter methylation of lactation-related genes using MassArray analysis in bovine mammary epithelial cells. The bovine mammary epithelial cell line MAC-T cells were treated for 48 h with LPS at different doses of 0, 1, 10, 100, and 1000 endotoxin units (EU)/mL (1 EU = 0.1 ng). The results showed that the genomic methylation levels and the number of methylated genes in the genome as well as the promoter methylation levels of milk genes increased when the LPS dose was raised from 0 to 10 EU/mL, but decreased after further increasing the LPS dose. The milk gene mRNA expression levels of the 10 EU/mL LPS treatment were significantly lower than these of untreated cells. The results also showed that the number of hypermethylated genes was greater than that of hypomethylated genes in lipid and amino acid metabolic pathways following 1 and 10 EU/mL LPS treatments as compared with control. By contrast, in the immune response pathway the number of hypomethylated genes increased with increasing LPS doses. The results indicate LPS at lower doses induced hypermethylation of the genome and promoters of lactation-related genes, affecting milk gene mRNA expression. However, LPS at higher doses induced hypomethylation of genes involved in the immune response pathway probably in favor of immune responses.

Treatment of corn with lactic acid or hydrochloric acid modulates the rumen and plasma metabolic profiles as well as inflammatory responses in beef steers.

BACKGROUND: High-grain diets that meet the energy requirements of high-producing ruminants are associated with a high risk of rumen disorders. Mild acid treatment with lactic acid (LA) has been used to modify the degradable characteristics of grains to improve the negative effects of high-grain diets. However, the related studies mainly focused on dairy cows and explored the effects on rumen fermentation, production performance, ruminal pH and so forth. And up to date, no studies have reported the hydrochloric acid (HA) treatment of grains for ruminant animals. Therefore, based on metabolomics analysis, the aim of this study was to evaluate the effects of treatment of corn by steeping in 1% LA or 1% HA for 48 h on the rumen and plasma metabolic profiles in beef steers fed a high corn (48.76%) diet with a 60:40 ratio of concentrate to roughage. The inflammatory responses of beef cattle fed LA- and HA-treated corn were also investigated. RESULTS: Based on ultra-high-performance liquid tandem chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) metabolomics and multivariate analyses, this study showed that steeping corn in 1% LA or 1% HA modulated the metabolic profiles of the rumen. Feeding beef steers corn steeped in 1% LA or 1% HA was associated with lower relative abundance of carbohydrate metabolites, amino acid metabolites, xanthine, uracil and DL-lactate in the rumen; with higher ruminal pH; with lower concentrations of acetate, iso-butyrate and iso-valerate; and with a tendency for lower ruminal lipopolysaccharide (LPS) concentrations. Moreover, the data showed lower concentrations of plasma C-reactive protein, serum amyloid A, haptoglobin, interleukin (IL)-1ß and IL-8 in beef steers fed 1% LA- or HA-treated corn. The 1% LA treatment decreased the concentrations of plasma LPS, LPS-binding protein and tumour necrosis factor-alpha and the relative abundance of L-phenylalanine, DL-3-phenyllactic acid and tyramine in plasma. The 1% HA treatment decreased the relative abundance of urea in plasma and increased the relative abundance of all amino acids in the plasma. CONCLUSIONS: These findings indicated that LA or HA treatment of corn modulated the degradation characteristics of starch, which contributed to improving the rumen and plasma metabolic profiles and to decreasing inflammatory responses in beef steers fed a high-concentrate diet.

Rumen and plasma metabolomics profiling by UHPLC-QTOF/MS revealed metabolic alterations associated with a high-corn diet in beef steers.

High-grain diets are strongly associated with metabolic disorders in beef steers. Metabolomics can be used to explore the relationship between diet and metabolic changes, but no study has reported rumen and plasma metabolomics profiling associated with increasing dietary corn proportions in the diet of beef steers. Therefore, 12 steers paired according to similar body weights and body condition scores were randomly allocated to one of two diets: a low-corn (28.76%) diet (LCD) with a 40:60 ratio of concentrate to roughage and a high-corn (48.76%) diet (HCD) with a 60:40 ratio of concentrate to roughage. Metabolomics profiling by ultra-high-performance liquid tandem chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF/MS) showed that steers fed the HCD had increased rumen and plasma carbohydrate metabolites and amino acids, which contributed to the growth of the beef steers. However, the rumen acidity and ruminal and plasma lipopolysaccharide (LPS) concentrations significantly increased with the increase amounts of corn in the diet. In total, 717 rumen metabolites and 386 plasma metabolites were identified. By multivariate analysis, 144 rumen and 56 plasma metabolites were further identified that were significantly different between the two groups (P < 0.05 and variable influence on projection > 1). The differential metabolites in the rumen and plasma were associated with different metabolic pathways, and phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism were common key metabolic pathways for the two biofluids. In conclusion, the high-corn diet improved the growth performance of beef steers but decreased the ruminal pH and increased the LPS and harmful metabolites in the rumen and blood, which has implications for the incidence of metabolic diseases. The identified differential metabolites in both the rumen and plasma and the related metabolic pathways may contribute to the exploration of potential biomarkers for high-corn diet-based metabolic diseases.

Responses to dietary levels of methionine in broilers medicated or vaccinated against coccidia under Eimeria tenella-challenged condition.

BACKGROUND: Coccidiosis is a prevalent problem in chicken production. Dietary addition of coccidiostats and vaccination are two approaches used to suppress coccidia in the practical production. Methionine (Met) is usually the first limiting amino acid that plays important roles in protein metabolism and immune functions in chickens. The present study is aimed to investigate whether increasing dietary Met levels will improve the anticoccidial effects in broilers medicated or vaccinated against coccidia under Eimeria (E.) tenella-challenged condition. Two thousand male Partridge Shank broiler chicks were obtained from a hatchery. After hatch, birds were weighed, color-marked and allocated equally into two anticoccidial treatments, namely medicated and vaccinated groups. Chicks were either fed, from 1 d of age, diets containing coccidiostat (narasin) or diets without the coccidiostat but were inoculated with an anticoccidial vaccine at 3 d of age. At 22 d of age, 1080 chicks among them were randomly allocated evenly into 6 groups under a 2 × 3 treatment with 2 anticoccidial programs and 3 dietary methionine (Met) levels. Chicks medicated or vaccinated against coccidia were fed diets containing 0.45%, 0.56% or 0.68% of Met from 22 to 42 d of age. All chicks were orally introduced with an amount of 5 × 104 sporulated oocysts of E. tenella at 24 d of age. The growth performance, serum anti-oxidative indexes, intestinal morphology, cecal lesion scores, fecal oocyst counts and immune parameters were measured. RESULTS: The results showed increasing dietary Met level from 0.45% to 0.56% and 0.68% improved weight gain and feed conversion of broilers medicated against coccidia. In contrast, higher dietary levels of Met did not improve growth performance of the vaccinated chickens. Higher Met levels helped the medicated chickens resist E. tenella infection, as indicated by improved intestinal morphology and immune functions as well as decreased cecal lesion and fecal oocyst counts. CONCLUSIONS: Anticoccidial vaccination is a better strategy for controlling coccidiosis than feeding narasin, due to not only greater growth performance, but also the lower Met supplementation. Furthermore, higher dietary Met levels improved growth performance of chickens medicated rather than vaccinated against coccidia under E. tenella-challenged condition.

WiFi-Based Real-Time Calibration-Free Passive Human Motion Detection.

With the rapid development of WLAN technology, wireless device-free passive human detection becomes a newly-developing technique and holds more potential to worldwide and ubiquitous smart applications. Recently, indoor fine-grained device-free passive human motion detection based on the PHY layer information is rapidly developed. Previous wireless device-free passive human detection systems either rely on deploying specialized systems with dense transmitter-receiver links or elaborate off-line training process, which blocks rapid deployment and weakens system robustness. In the paper, we explore to research a novel fine-grained real-time calibration-free device-free passive human motion via physical layer information, which is independent of indoor scenarios and needs no prior-calibration and normal profile. We investigate sensitivities of amplitude and phase to human motion, and discover that phase feature is more sensitive to human motion, especially to slow human motion. Aiming at lightweight and robust device-free passive human motion detection, we develop two novel and practical schemes: short-term averaged variance ratio (SVR) and long-term averaged variance ratio (LVR). We realize system design with commercial WiFi devices and evaluate it in typical multipath-rich indoor scenarios. As demonstrated in the experiments, our approach can achieve a high detection rate and low false positive rate.

Effects of dietary energy level on lipid metabolism-related gene expression in subcutaneous adipose tissue of Yellow breed x Simmental cattle.

This study was conducted to estimate the effect of dietary energy level on lipid metabolism-related gene expression of subcutaneous adipose tissue in Yellow breed × Simmental cattle. The experiment was conducted for 60 days. The results showed that final weight, average daily gain, average backfat thickness, (testicles + kidney + pelvic) fat percentage and subcutaneous fat percentage in the high and medium energy groups were significantly higher than in the low-energy group but that the feed conversion ratio was significantly lower. The glucose, triglycerides, cholesterol, high-density lipoprotein and low-density lipoprotein in the high-energy group were significantly higher than in the low-energy group. With dietary energy increasing the activities of lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) significantly increased, whereas hormone-sensitive lipase (HSL) and carnitine palmitoyltransferase-1 (CPT-1) significantly diminished. Peroxisome proliferator-activated receptor γ (PPARγ), LPL, FAS, sterol regulatory element binding protein 1 (SREBP-1), ACC, stearoyl-CoA desaturase (SCD) and adipocyte-fatty acid binding proteins (A-FABP) gene expression were significantly increased by dietary energy increasing, and HSL and CPT-1 gene expression were significantly decreased. These results indicated that with dietary energy increasing, the subcutaneous fat accumulation mainly increased due to adipose tissue lipogenic gene expression and decreased lipolytic gene expression.

Feeding a high-concentrate corn straw diet induced epigenetic alterations in the mammary tissue of dairy cows.

PURPOSE: The objective of this study was to investigate the effects of feeding a high-concentrate corn straw (HCS) diet (65% concentrate+35% corn straw) on the epigenetic changes in the mammary tissue of dairy cows in comparison with a low-concentrate corn straw (LCS) diet (46% concentrate+54% corn straw) and with a low-concentrate mixed forage (LMF) diet (46% concentrate+54% mixed forage). EXPERIMENTAL DESIGN: Multiparous mid-lactation Chinese Holstein cows were fed one of these three diets for 6 weeks, at which time blood samples and mammary tissue samples were collected. Mammary arterial and venous blood samples were analyzed for lipopolysaccharide (LPS) concentrations while mammary tissue samples were assayed for histone H3 acetylation and the methylation of specific genes associated with fat and protein synthesis. RESULTS: Extraction of histones and quantification of histone H3 acetylation revealed that acetylation was significantly reduced in cows fed the HCS diet, as compared with cows fed the LCS diet. Cows fed the HCS diet had significantly higher LPS concentrations in the mammary arterial blood, as compared with cows fed the LCS diet. We found that the extent of histone H3 acetylation was negatively correlated with LPS concentrations. The methylation of the stearoyl-coenzyme A desaturase gene associated with milk fat synthesis was increased in cows fed the HCS diet. By contrast, methylation of the gene encoding the signal transducer and activator of transcription 5A was reduced in cows fed the HCS diet, suggesting that feeding a high-concentrate corn straw diet may alter the methylation of specific genes involved in fat and protein synthesis in the mammary tissue of dairy cows. CONCLUSIONS: Feeding the high-concentrate diet induced epigenetic changes in the mammary tissues of dairy cows, possibly through effecting the release of differing amounts of LPS into the mammary blood.

Feeding a high-concentrate corn straw diet increased the release of endotoxin in the rumen and pro-inflammatory cytokines in the mammary gland of dairy cows.

BACKGROUND: The objective of this study was to investigate the effects of feeding a high-concentrate corn straw diet on the release of endotoxin in the rumen and the changes of pro-inflammatory cytokines in the mammary gland of dairy cows in comparison with a low-concentrate corn straw diet and a low-concentrate mixed forage diet. Thirty second-parity Chinese Holstein cows in mid-lactation with a body condition score of 2.86 ± 0.29, weighing 543 ± 57 kg and producing 24.32 ± 3.86 kg milk per day were randomly assigned to 1 of the 3 diets (n = 10 per treatment): 1) low-concentrate mixed forage diet (LCF) with a concentrate to roughage ratio of 46 : 54; 2) high-concentrate corn straw diet (HCS) with a concentrate to roughage ratio of 65 : 35; 3) low-concentrate corn straw diet (LCS) with the same concentrate to roughage ratio (46 : 54) as LCF. The experiment lasted 6 weeks, and samples were collected in the last week. Milk samples were analyzed for conventional components, rumen fluid samples were analyzed for pH and endotoxin, and mammary arterial and venous plasma samples were analyzed for concentrations of interleukin (IL)-1ß, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). RESULTS: Concentrations of endotoxin in rumen fluid and feces of cows fed HCS were significantly higher than those of cows fed LCS and LCF. Feeding HCS increased the release of IL-1ß, IL-6 and IL-8 in the mammary gland compared with feeding LCS. Concentrations of cytokines (IL-1ß and IL-8) in mammary venous plasma had a negative correlation with milk production efficiencies. CONCLUSIONS: Results indicated that the high-concentrate corn straw diet increased the concentrations of endotoxin in rumen fluid and feces. Furthermore, feeding the high-concentrate corn straw diet stimulated the mammary gland to release more pro-inflammatory cytokines. The results suggest that feeding a high-concentrate corn straw diet induce a higher pro-inflammatory response in the mammary gland and thus may partly decrease the milk production efficiencies in dairy cows.