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The objective of this study was to investigate whether supplementation with N-carbamoylglutamate (NCG) to cows during late gestation alters uteroplacental tissue nutrient transporters, calf metabolism and newborn weight. Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a diet without (CON) or with NCG (20 g/d per cow). The body weight of calves was weighed immediately after birth. Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine, glucose, fatty acid and angiogenesis factors, as well as the mammalian target of rapamycin (mTOR) pathway. Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters, amino acids (AA) and metabolomics analysis. The newborn weight (P = 0.02) and plasma Arg concentration of NCG-calves was significantly higher (P = 0.05) than that of CON-calves, and the plasma concentrations of urea nitrogen tended to be lower (P = 0.10) in the NCG group. The mRNA abundance of genes involved in glucose transport (solute carrier family 2 member 3 [SLC2A3], P < 0.01), angiogenesis (nitric oxide synthase 3 [NOS3], P = 0.02), and mTOR pathway (serine/threonine-protein kinase 1 [AKT1], P = 0.10; eukaryotic translation initiation factor 4B pseudogene 1 [EIF4BP1], P = 0.08; EIF4EBP2, P = 0.04; and E74-like factor 2 [ELF2], P = 0.03) was upregulated in the placentome of NCG-supplemented cows. In addition, 17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows, and these metabolites are mainly involved in arginine and proline metabolism, alanine, aspartate and glutamate metabolism, and citrate cycle. In summary, the increased body weight of newborn calves from the NCG supplemented dairy cows may be attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway, which may result in the increased nutrient supply to the fetus, and improved AA metabolism and urea cycle of the fetus.

The objective of this study was to investigate the effects of supplementing N-carbamoylglutamate (NCG), an Arg enhancer, on amino acid (AA) supply and utilization and productive performance of early-lactating dairy cows. Thirty multiparous Chinese Holstein dairy cows were randomly divided into control (CON, n = 15) and NCG (CON diet supplemented with NCG at 20 g/d per cow, n = 15) groups at 4 wk before calving. Diets were offered individually in tie-stalls, and NCG was supplemented by top-dress feeding onto total mixed ration for the NCG group. The experiment lasted until wk 10 after calving. Dry matter intake tended to be higher (P = 0.06), and yields of milk (P

N-Carbamoylglutamate (NCG) is an enhancer of Arg, which is a functional AA and could prevent cardiovascular disease and improve immunity. The present study was conducted to investigate the effects of supplementing NCG in diets of lactating cattle on the NCG concentration and AA composition of raw milk and on mozzarella cheese quality. Thirty multiparous cows with a mean body weight of 669 kg (standard deviation = 71) and days in milk of 176 (standard deviation = 55) were blocked based on parity and milk production and randomly assigned to 1 of 2 treatments: basal diet (CON) and basal diet supplemented with 40 g of NCG per day per cow (NCG). After 8 wk of treatment, raw milk samples were collected from the 2 groups for AA analysis and mozzarella cheese-making. Furthermore, the NCG concentration and distribution in milk and mozzarella cheese were detected. The AA concentration in milk was greater and the NCG concentration in raw milk was approximately 6 times greater in the NCG group than in the CON group. No NCG was detected in cheese from the CON group, and very little NCG (

Dairy cattle are a vitally important ruminant in meeting the demands for high-quality animal protein production worldwide. The complicated biological process of converting human indigestible biomass into highly digestible and nutritious milk is orchestrated by various tissues. However, poorly understanding of the cellular composition and function of the key metabolic tissues hinders the improvement of health and performance of domestic ruminants.The cellular heterogeneity, metabolic features, interactions across ten tissue types of lactating dairy cattle were studied at single-cell resolution in the current study.Unbiased single-cell RNA-sequencing and analysis were performed on the rumen, reticulum, omasum, abomasum, ileum, rectum, liver, salivary gland, mammary gland, and peripheral blood of lactating dairy cattle. Immunofluorescences and fluorescence in situ hybridization were performed to verify cell identity.In this study, we constructed a single-cell landscape covering 88,013 high-quality (500 genes 4,000, UMI 50, 000, and mitochondrial gene ratio 40% or 15%) single cells and identified 55 major cell types in lactating dairy cattle. Our systematic survey of the gene expression profiles and metabolic features of epithelial cells related to nutrient transport revealed cell subtypes that have preferential absorption of different nutrients. Importantly, we found that T helper type 17 (Th17) cells (highly expressingThe findings enhance our understanding of the cellular biology of ruminants and open new avenues for improved animal production of dairy cattle.

BackgroundThe rumen is the hallmark organ of ruminants, playing a vital role in their nutrition and providing products for humans. In newborn suckling ruminants milk bypasses the rumen, while in adults this first chamber of the forestomach has developed to become the principal site of microbial fermentation of plant fibers. With the advent of single-cell transcriptomics, it is now possible to study the underlying cell composition of rumen tissues and investigate how this relates the development of mutualistic symbiosis between the rumen and its epithelium-attached microbes.ResultsWe constructed a comprehensive cell landscape of the rumen epithelium, based on single-cell RNA sequencing of 49,689 high-quality single cells from newborn and adult rumen tissues. Our single-cell analysis identified six immune cell subtypes and seventeen non-immune cell subtypes of the rumen. On performing cross-species analysis of orthologous genes expressed in epithelial cells of cattle rumen and the human stomach and skin, we observed that the species difference overrides any cross-species cell-type similarity. Comparing adult with newborn cattle samples, we found fewer epithelial cell subtypes and more abundant immune cells, dominated by T helper type 17 cells in the rumen tissue of adult cattle. In newborns, there were more fibroblasts and myofibroblasts, anIGFBP3+epithelial cell subtype not seen in adults, while dendritic cells were the most prevalent immune cell subtype. Metabolism-related functions and the oxidation-reduction process were significantly upregulated in adult rumen epithelial cells. Using 16S rDNA sequencing, fluorescence in situ hybridization, and absolute quantitative real-time PCR, we found that epithelialDesulfovibriowas significantly enriched in the adult cattle. Integrating the microbiome and metabolome analysis of rumen tissues revealed a high co-occurrence probability ofDesulfovibriowith pyridoxal in the adult cattle compared with newborn ones while the scRNA-seq data indicated a stronger ability of pyroxidal binding in the adult rumen epithelial cell subtypes. These findings indicate thatDesulfovibrioand pyridoxal likely play important roles in maintaining redox balance in the adult rumen.ConclusionsOur integrated multi-omics analysis provides novel insights into rumen development and function and may facilitate the future precision improvement of rumen function and milk/meat production in cattle.

Background: Cow’s milk is a highly-nutritious dairy product that is widely consumed worldwide. It is secreted by the developed mammary gland (MG) of dairy cattle. However, a comprehensive understanding of cell-type diversity and cell function within bovine MG is lacking. In the current study, we used single-cell RNA sequencing to investigate the transcriptome of 24,472 high-quality MG cells isolated from newborn and adult cows. Results: Unbiased clustering analysis revealed the existence of 24 cell types, which could be divided into four categories: 9 immune, 3 epithelial, 9 fibroblast, and 3 endothelial cell types. Other cell subtypes were further identified based on re-clustering and pseudotemporal reconstruction of epithelial cells that included 3 mature luminal epithelial, 1 intermediate, and 2 progenitor cell subtypes. The individual top marker genes of these 3 mature luminal epithelial cell subtypes (L0, L1, and L5) were APOA1, STC2, and PTX3, which were further validated using immunofluorescence. Based on functional analysis, the L0, L1, and L5 cell subtypes were all involved in the upregulation of lipid metabolism, protein and hormone metabolism, and the immune response, respectively. Furthermore, we discovered a novel myofibroblast that expresses COL1A1 and CSN3, has visible epithelial-like characteristics, and shows the potential to differentiate into luminal epithelial cells, especially immune-sensing luminal cells (L5). Conclusions: We constructed the first single-cell atlas of the dairy cow MG, and our new findings of epithelial-like myofibroblast cells and their differentiation trajectories into luminal cells may provide novel insights into the development and lactogenesis in dairy cattle MGs.

Background N-carbamoylglutamate (NCG), a structural analog of N-acetylglutamate that is essential for endogenous arginine synthesis, has unique advantages, including low rumen degradability, low cost, and a lack of negative effects on intestinal absorption of dietary histidine and lysine. Information is limited on the effect of dietary NCG on the reproduction performance of the late-gestation dairy cows. The objective of this study was to investigate whether supplementation of NCG to cows during late gestation alters uteroplacental tissue nutrient transporters, calf metabolism and newborn weight. Results Thirty multiparous Chinese Holstein cows were used in an experiment with a randomized complete block design. During the last 28 d of pregnancy, cows were fed a diet without (CON) or with NCG (20 g/d/cow). The mRNA expression of genes related to arginine, glucose, and fatty acid transporters, angiogenesis factors and the mTOR pathway in the placentome were analyzed. Blood samples of calves were collected for analysis of plasma parameters, amino acids, and metabolites. The newborn weight (P P = 0.07) were higher in NCG calves than in CON calves. The mRNA expression of genes involved in glucose transport, angiogenesis and the mTOR pathway in the placenta was upregulated (P

Cow’s milk is a highly-nutritious dairy product part of human diet worldwide. Rumen-protected methionine (RPM) is widely used to improve lactation performance of dairy cows, but understanding of the effects of RPM on milk nutrients composition are still limited. In this study, twenty mid-lactating dairy cows were supplemented with 20 gm/day RPM for 8 weeks to investigate the responses of milk nutritional composition to RPM. Metabolomics was applied for analyzing milk metabolites and 16S rRNA gene sequencing was used for analysis of rumen microbial composition. Milk fat content and yield were significantly increased after RPM supplementation. Totally 443 compounds belonging to 15 classes were identified, among which 15 metabolites were significantly changed. The functional nutrient α-ketoglutaric acid were significantly increased in the milk after RPM supplementation. We found 48 significantly differing bacterial genera in the rumen after supplementing RPM. Multi-omics integrated analysis revealed the higher abundance of Acetobacter, unclassified_f_Lachnospiraceae and Saccharofermentan contributed to the improved milk fat. In addition, the enriched abundance of Thermoactinomyces, Asteroleplasma, and Saccharofermentan showed positive correlations with higher α-ketoglutaric acid of milk. Our results uncover the metabolomic fingerprint and the key functional metabolites in the milk after supplementing RPM in dairy cows, as well as the key rumen bacteria associated with them. These findings provide novel insights into the development of functional dairy products that enriched the functional nutrient α-ketoglutaric acid or high milk fat.

The present study was conducted to investigate the effect of N-carbamoylglutamate (NCG) on milk production and composition in mid-lactating Holstein dairy cows. Sixty multiparous cows with a mean body weight of 669 kg (standard deviation = 71) and 176 days in milk (standard deviation = 55) were blocked based on parity and milk production and randomly assigned into 4 treatments, a basal diet supplemented with 0, 10, 20, or 40 g of NCG/d per cow. Milk yield and composition were recorded weekly, whereas dry matter intake and plasma variables were determined every 2 wk. The results showed that the addition of NCG had no effect on the dry matter intake and milk yield of the cows. Milk fat content and yield increased linearly with NCG addition. The contents of milk protein and total solid also increased linearly in the cows fed NCG, whereas the yield of protein was not affected by the treatments. Conversely, dietary addition of NCG increased the plasma nitric oxide content in a quadratic manner. Moreover, addition of NCG linearly increased the plasma Arg content. Overall, the results indicate that dietary NCG addition increased the milk protein and fat contents, which improved the milk quality of lactating dairy cows.