Project description:The objective of this study was to characterize the mRNA expression profile in rumen epithelium from Holstein dairy cows fed high or low concentrate dits.
Project description:Nitrogen (N) emissions became a huge topic under environmental and nutrient concerns in dairy farming. Nitrogen is metabolized in cows as a consequence of feed crude protein digestion which is either recycled or excreted via urine, faeces and/or milk. In dairy cows differences between cows in N-recycling and N-emissions have been postulated. This study investigated 24 Holstein dairy cows in late lactation. The experimental design comprises two dietary groups (low (LP) vs normal (NP) crude protein) and two groups of milk urea content, high (HMU) vs low (LMU). Transcriptomic profiles of the liver, rumen, mammalian gland and kidney tissues were comparatively assessed by mRNA sequencing.
Project description:In dairy cows, administration of high dosages of niacin (NA) was found to cause anti-lipolytic effects, which are mediated by the NA receptor hydroxyl-carboxylic acid receptor 2 (HCAR2) in white adipose tissue (WAT), and thereby to an altered hepatic lipid metabolism. However, almost no attention has been paid to possible direct effects of NA in cattle liver, despite showing that HCAR2 is expressed also in the liver of cattle and is even more abundant than in WAT. Due to this, we hypothesized that feeding of rumen-protected NA to dairy cows influences critical metabolic and/or signaling pathways in the liver through inducing changes in the hepatic transcriptome. In order to identify these pathways, we applied genome-wide transcript profiling in liver biopsies obtained at 1 wk postpartum (p.p.) from dairy cows of a recent study (Zeitz et al., 2018) which were fed a total mixed ration without (control group) or with rumen-protected NA from 21 d before calving until 3 wk p.p. Hepatic transcript profiling revealed that a total of 487 transcripts were differentially expressed [filter criteria fold change (FC) > 1.2 or FC < -1.2 and P < 0.05] in the liver at 1 wk p.p. between cows fed NA and control cows. Substantially more transcripts were down-regulated (n = 338), while only 149 transcripts were up-regulated by NA in the liver of cows. Gene set enrichment analysis (GSEA) for the up-regulated transcripts revealed that the most enriched gene ontology (GO) biological process terms were exclusively related to immune processes, such as leukocyte differentiation, immune system process, leukocyte differentiation, activation of immune response and acute inflammatory response. In line with this, the plasma concentration of the acute phase protein haptoglobin tended to be increased in dairy cows fed rumen-protected NA compared to control cows (P < 0.1). GSEA of the down-regulated transcripts showed that the most enriched biological process terms were related to metabolic processes, such as cellular metabolic process, small molecule metabolic process, lipid catabolic process, organic cyclic compound metabolic process, small molecule biosynthetic process and cellular lipid catabolic process. In conclusion, hepatic transcriptome analysis shows that rumen-protected NA induces genes which are involved mainly in immune processes including acute phase response and stress response in dairy cows at wk 1 p.p. These findings indicate that supplementation of rumen-protected NA to dairy cows in the periparturient period may induce or amplify the systemic inflammation-like condition which is typically observed in the liver of high-yielding dairy cows in the p.p. period.
Project description:We performed single-cell RNA-sequencing on the rumen epithelium of dairy cows to construct an epithelial single-cell map of the rumen.
Project description:In this study, we investigated the molecular regulatory mechanisms of milk protein production in dairy cows by studying the miRNAomes of five key metabolic tissues involved in protein synthesis and metabolism from dairy cows fed high- and low-quality diets. In total, 340, 338, 337, 330, and 328 miRNAs were expressed in the rumen, duodenum, jejunum, liver, and mammary gland tissues, respectively. Some miRNAs were highly correlated with feed and nitrogen efficiency, with target genes involved in transportation and phosphorylation of amino acid (AA). Additionally, low-quality forage diets (corn stover and rice straw) influenced the expression of feed and nitrogen efficiency-associated miRNAs such as miR-99b in rumen, miR-2336 in duodenum, miR-652 in jejunum, miR-1 in liver, and miR-181a in mammary gland. Ruminal miR-21-3p and liver miR-2285f were predicted to regulate AA transportation by targeting ATP1A2 and SLC7A8, respectively. Furthermore, bovine-specific miRNAs regulated the proliferation and morphology of rumen epithelium, as well as the metabolism of liver lipids and branched-chain AAs, revealing bovine-specific mechanisms. Our results suggest that miRNAs expressed in these five tissues play roles in regulating transportation of AA for downstream milk production, which is an important mechanism that may be associated with low milk protein under lowquality forage feed.
2018-07-21 | GSE117441 | GEO
Project description:Rumen fluid sequencing of high versus low producing dairy cows
| PRJNA1006003 | ENA
Project description:High and low efficiency dairy cows
Project description:The current situation of rising demand for animal products and sustainable resource usage, improving nutrient utilization efficiency in dairy cows is an important task. Understanding the biology of feed efficiency in dairy cows enables for the development of markers that may be used to identify and choose the best animals for animal production. Thus in this study, ten Holstein cows were evaluated for feed efficiency and adipose tissue samples from five high efficient and five low efficient dairy cows were collected for protein extraction, digestion and data were analyzed for differential abundant proteins enriched in feed efficiency pathways. Among the identified peptides, we found 110 DAPs and two protein networks significantly related to feed efficiency. Among the relative mRNA expression of genes involved in energy metabolism including transcription/translation (STAT2, DDX39A and RBM39) or protein transport (ITGAV), only RBM39 showed significant decrease in high efficient dairy cows. The findings presented here confirmed the Transferrin upregulated in pathways including acute phase response signaling, LXR/RXR activation, FXR/RXR activation of high efficient dairy cows supporting that these pathways are related to feed efficiency in dairy cows.
Project description:In the present study, transcript profiling was carried out in the liver samples from wk 5 of lactation in order to identify genes and pathways regulated by rumen-protected CLA during early lactation. The first wks after parturition represent a critical phase in the productive cycle of high-yielding dairy cows because the liver experiences pronounced metabolic and inflammatory stress which increases the risk to develop liver-associated diseases, such as fatty liver and ketosis.
Project description:M. Berg, J. Plöntzke, S. Leonhard-Marek, K.E. Müller & S. Röblitz. A dynamic model to simulate potassium balance in dairy cows. Journal of Dairy Science 100, 12 (2017).
High-performing dairy cows require a particular composition of nutritional ingredients, adapted to their individual requirements and depending on their production status. The optimal dimensioning of minerals in the diet, one being potassium, is indispensable for the prevention of imbalances. Potassium balance in cows is the result of potassium intake, distribution in the organism, and excretion, and it is closely related to glucose and electrolyte metabolism. In this paper, we present a dynamical model for potassium balance in lactating and nonlactating dairy cows based on ordinary differential equations. Parameter values were obtained from clinical trial data and from the literature. To verify the consistency of the model, we present simulation outcomes for 3 different scenarios: potassium balance in (1) nonlactating cows with varying feed intake, (2) nonlactating cows with varying potassium fraction in the diet, and (3) lactating cows with varying milk production levels. The results give insights into the short- and long-term potassium metabolism, providing an important step toward the understanding of the potassium network, the design of prophylactic feed additives, and possible treatment strategies.