Project description:Heat stress (HS) has become a major challenge in the dairy industry around the world. Although numerous measures have been taken to alleviate the HS impact on milk production, the cellular level response to HS remains unclear in dairy cows. The objective of this study was to dissect functional alterations based on transcriptomic dynamics in the liver of cows under HS. Dairy cows exposed to HS exhibited both decreased feed intake and milk yield. Through liver transcriptomic analysis, differentially expressed genes were identified among three experimental conditions, including heat stress (HS), pair-fed (PF), and thermoneutral (TN) groups. We observed the upregulation of protein folding and inflammation-related genes in the HS group, while the mitochondrial genes were downregulated. Gene functional enrichment also revealed that mitochondria function and oxidative phosphorylation were dysregulated under HS. The liver transcriptome analysis generated a comprehensive gene expression regulation network upon HS in lactating dairy cows. Overall, this study provides novel insights into molecular and metabolic changes of cows conditioned under HS. Our results could facilitate the development of efficient biomarkers to mitigate the negative effect of HS on dairy cow health and productivity.
Project description:In this study, samples of 16 dairy cows from a MAP infected farm were used. Serum, milk and fecal samples were collected. Categorizing these cows into two groups based on their MAP infection status different standard methods for detection MAP were applied. Healthy controls showed no positive results in enzyme-linked immunosorbent assay (ELISA) with serum and milk samples (cattletype MAP Ab, Qiagen, Hilden, Germany; In-direct, IDVet, Grabels, France) and after cultivation of fecal samples on commercial Her-rold´s Egg Yolk Agars (HEYM agar, Becton Dickinson, Heidelberg, Germany) for 12 weeks. Cows with positive results were grouped into MAP infected cows. Specifically, for mass spectrometry analysis serum of seven MAP infected cows and seven healthy controls were used. All animals were from the same farm and were kept under the same environmental conditions. For additional mass spectrometry analysis with a further control group sam-ples of 21 dairy cows from an uninfected farm were examined. All cattle from this farm showed negative results in ELISA with serum and milk samples. Additionally, there was never a positive result in regularly tested fecal samples and sock swab samples of this farm. For verification of differential CTSS expression in Western blot analysis five dairy cows from another infected farm were consultedincluded. MAP status of these cows was analyzed by cultivation of fecal samples on HEYM agar for 12 weeks and ELISA with se-rum samples. In detail, two cattle were categorized into healthy controls and three cattle into MAP infected cows. Withdrawal of bovine venous whole blood and experi-mental protocols were approved by the local authority, Government of Upper Bavaria, permit no. ROB-55.2-2532.Vet_03-17-106.
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:The transition to lactation challenges dairy cows metabolically. Immune dysfunction and infectious disease risk is the hallmark of this transition period. Transcriptome data of PBMC shows differentially expressed pathways postpartum. Metabolically stressed cows show upregulation of innate immune pathways and inflammation.
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.
Project description:The aim of this study was to determine the effects of linseed dietary supplementation on gene expression in the mammary gland of grazing dairy cows. Milk composition and gene expression in the mammary gland tissue were evaluated in dairy cows supplemented with linseed. The linseed supplementation improves the health and nutrition quality aspects of dairy milk, but also affects the gene networks expression signature associated with cellular growth and proliferation, cell-death, signalling, nutrient metabolism, and immune response, and in turn, the mammary gland integrity and health.