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 severity of negative energy balance (NEB) in high-producing dairy cows has a high incidence among health diseases. The periparturient period is crucial for the health status and reproductive performance of dairy cows. During this period, dairy cows experience a transition from a pregnant, non-lactating state to a non-pregnant, lactating state. At the beginning of lactation, the energy needs for milk production are higher than the available energy consumed from feed intake, resulting in a negative energy balance (NEB)]. While in a NEB, cows mobilise their reserves from adipose tissue, resulting in elevated plasma concentrations of non-esterified fatty acids (NEFAs), which are used as a fuel source by peripheral tissues and the mammary gland for milk fat synthesis. Thus, white adipose tissue is one of the main tissue involved in the energy production during this transition period. So the objectives of our study were to dentify mRNA differentially expressed in white adipose before and after calving in dairy cow fed with low (LE) and high (HE) energy diet.
Project description:Previous work has demonstrated that elevated maternal lipid intake (particularly from dairy products) is associated with increased lipids and altered fatty acid profile in milk produced by healthy lactating women. We investigate our primary hypothesis that a maternal diet rich in full-fat dairy products would simultaneously increase milk lipid percent and expression of genes related to the uptake and/or de novo biosynthesis of milk lipids.
Project description:Analysis of key genes and gene networks determining milk productivity of the dairy HF cows Transcriptomes were compared of in the mammary glands of the healthy lactating Holstein Friesian cows of the high- (average 11097 kg milk/lactation) and low- (average 6956 kg milk/lactation) milk yield.
Project description:Previous work has demonstrated that elevated maternal lipid intake (particularly from dairy products) is associated with increased lipids and altered fatty acid profile in milk produced by healthy lactating women. We investigate our primary hypothesis that a maternal diet rich in full-fat dairy products would simultaneously increase milk lipid percent and expression of genes related to the uptake and/or de novo biosynthesis of milk lipids. Within a a randomized, crossover study we performed a microarray analysis comparing 6 lactating women with diets rich in full-fat or non-fat dairy products. Each woman consumed one of the two diets during timepoint one, and after a two week washout period, switched over to the other diet. The timepoint value indicates whether the particular dietary treatment was consumed first or second.
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: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.
2023-08-08 | GSE226351 | GEO
Project description:Grape seed extract supplementation altered the rumen microbiota composition in dairy cows
Project description:<p><strong>BACKGROUND:</strong> Lactation is extremely important for dairy cows; however, the understanding of the underlying metabolic mechanisms is very limited. This study was conducted to investigate the inherent metabolic patterns during lactation using the overall biofluid metabolomics and the metabolic differences from non-lactation periods, as determined using partial tissue-metabolomics. We analyzed the metabolomic profiles of four biofluids (rumen fluid, serum, milk and urine) and their relationships in six mid-lactation Holstein cows and compared their mammary gland (MG) metabolomic profiles with those of six non-lactating cows by using gas chromatography-time of flight/mass spectrometry. </p><p><strong>RESULTS:</strong> In total, 33 metabolites were shared among the four biofluids, and 274 metabolites were identified in the MG tissues. The sub-clusters of the hierarchical clustering analysis revealed that the rumen fluid and serum metabolomics profiles were grouped together and highly correlated but were separate from those for milk. Urine had the most different profile compared to the other three biofluids. Creatine was identified as the most different metabolite among the four biofluids (VIP=1.537). Five metabolic pathways, including gluconeogenesis, pyruvate metabolism, the tricarboxylic acid cycle (TCA cycle), glycerolipid metabolism, and aspartate metabolism, showed the most functional enrichment among the four biofluids (false discovery rate<0.05, fold enrichment >2). Clear discriminations were observed in the MG metabolomics profiles between the lactating and non-lactating cows, with 54 metabolites having a significantly higher abundance (P<0.05, VIP>1) in the lactation group. Lactobionic acid, citric acid, orotic acid and oxamide were extracted by the S-plot as potential biomarkers of the metabolic difference between lactation and non-lactation. The TCA cycle, glyoxylate and dicarboxylate metabolism, glutamate metabolism and glycine metabolism were determined to be pathways that were significantly impacted (P<0.01, impact value >0.1) in the lactation group. Among them, the TCA cycle was the most up-regulated pathway (P<0.0001), with 7 of the 10 related metabolites increased in the MG tissues of the lactating cows. </p><p><strong>CONCLUSIONS:</strong> The overall biofluid and MG tissue metabolic mechanisms in the lactating cows were interpreted in this study. Our findings are the first to provide an integrated insight and a better understanding of the metabolic mechanism of lactation, which is beneficial for developing regulated strategies to improve the metabolic status of lactating dairy cows.</p>
Project description:Milk protein is one of the most important economic traits in the dairy industry. Yet, the miRNA gene regulatory network for the synthesis of milk protein in mammary is poorly understood. In this study, the hypothesis was that miRNAs have potential roles in bovine milk protein production. Using miRNA-seq and RNA-seq, we investigated the miRNAs profiles of mammary glands from 12 Chinese Holstein cows with six cows at peak of lactation and six in non-lactating period, from which three cows were in high and three in low milk protein percentage.