Project description:In dairy cows, milk production and composition are affected by numerous factors, including diet. Milk is the body fluid with the highest RNA concentration, including numerous microRNA. These microRNA presence in the different milk compartments is still poorly documented and the effect of feed restriction on milk miRNome has not been described yet. The aim of this study was to describe the effects of feed restrictions of different intensitizes on milk compartment miRNome composition. Two feed restriction trials were performed on lactating dairy cows, one of high intensity and one of moderate intensity. 2 896 mature microRNA were identified in milk, including 1 493 that were already known in bovine specie. Among the 1 095 miRNA that were abundant enough to be informative, 10% were exclusive to one milk compartment and the abundance of 155 varied between compartments, revealing a specific miRNome for each milk fraction. Feed restriction affected differently these miRNome, with microRNA in whole milk and milk extracellular vesicles being the most affected and microRNA in fat globules and exfoliated mammary epithelial cells being relatively or completely unaffected. Target prediction of known microRNA that varied under feed restriction reflected modification of some key pathways for lactation related to milk fat and protein metabolisms, cell cycle and stress responses. These findings open up opportunities for future research on the use of milk miRNA as biomarkers of energy status in dairy cows.
Project description:This research investigates the influence of nutritional protein restriction (NPR) during prepuberty on FE and the milk transcriptome of dairy Assaf ewes during their first lactation. Additionally, it evaluates the differences in the milk transcriptome between lactating ewes with divergent FE using the feed conversion ratio (FCR) and residual feed intake (RFI) indices and assesses milk gene expression as a predictor of FE.
Project description:The nutritional value of goat milk varies depending on the lactation time(Y. Zhang, Zheng, Liu, & Liu, 2020). Tandem mass tagging (TMT) was employed in this study to explore the differential proteome of mature milk and terminal milk from Guanzhong dairy goats. Goat mature milk was beneficial in the treatment and improvement of malaria patients, as well as in the treatment of pancreatic cancer patients. Terminal milk has been proven to promote angiogenesis, boost antibacterial and anti-inflammatory factor activity, and inhibit tumor formation. These bioinformatics investigations will provide new insights into the physiological activities of proteins in goat milk from Guanzhong dairy goats, as well as a scientific foundation for future study into the creation of specialized functionalised dairy products, such as cancer prevention.
Project description:The aim of the present study was to correlate lipid metabolism genes in the mammary gland tissue affected by stage of lactation and nutrition to the resulting milk fatty acids composition in grazing dairy cows, and to classify milk fatty acid (FA) groups based on variations in lipid metabolism gene expression patterns. Identifying the relationship between lipid metabolism genes in the mammary gland tissue and the resulting milk fatty acid composition is expected to greatly contribute to our understanding of milk fatty acid metabolism and to enhance opportunities to improve milk fat composition through nutrition. In fact, SNCA, SCD5, and PNPLA2 lipid metabolism-related genes affected by unsaturated fatty acids supplementation, were found to strongly correlated to different milk FA groups, but also contributed most to the classification of these FA groups, suggesting a significant role in mediating the lipid metabolism in the mammary gland tissue and determining the milk fatty acids composition. A total of 28 Holstein-Friesian dairy cows in mid-lactation were blocked according to parity (2.4 ± 0.63 years), days in milk (DIM; 153 ± 32.8 days), milk yield (25.7 ± 3.08 kg/d) and fat content (4.3 ± 0.12%). Cows were then randomly assigned to four UFA-sources based on rapeseed, soybean, linseed or a mixture of the three oils for 23 days (Period I) after which, all 28 cows were switched to a control diet for an additional 28 days (Period II). On the last day of both periods, mammary gland biopsies were taken to study genome-wide differences in lipid metabolism gene expression.
Project description:Dietary supplementation with fish-oil modulates ruminant milk composition towards a healthier fatty acid profile for consumers, but it also causes milk fat depression (MFD). Because the dairy goat industry is mainly oriented towards cheese manufacturing, MFD can elicit economic losses. There is large individual variation in animal susceptibility with goats more (RESPO+) or less (RESPO−) responsive to diet-induced MFD. Thus, we used RNA-Seq to examine gene expression profiles in mammary cells to elucidate mechanisms underlying MFD in goats and individual variation in the extent of diet-induced MFD.
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:To investigate the molecular bases of diet induced differences in milk composition, we collected milk from mid lactation dairy ewes and after 3 weeks of diet supplementation with extruded linseed. RNAs were isolated from milk somatic cells isolated from milk of 3 sheep and Illumina RNA sequencing was performed to analyze RNA synthesis in these cells.
Project description:The aim of the present study was to correlate lipid metabolism genes in the mammary gland tissue affected by stage of lactation and nutrition to the resulting milk fatty acids composition in grazing dairy cows, and to classify milk fatty acid (FA) groups based on variations in lipid metabolism gene expression patterns. Identifying the relationship between lipid metabolism genes in the mammary gland tissue and the resulting milk fatty acid composition is expected to greatly contribute to our understanding of milk fatty acid metabolism and to enhance opportunities to improve milk fat composition through nutrition. In fact, SNCA, SCD5, and PNPLA2 lipid metabolism-related genes affected by unsaturated fatty acids supplementation, were found to strongly correlated to different milk FA groups, but also contributed most to the classification of these FA groups, suggesting a significant role in mediating the lipid metabolism in the mammary gland tissue and determining the milk fatty acids composition.
Project description:The knowledge of the genetic architecture behind feed efficiency would allow to breed more efficient animals maximizing farm profitability and reducing the environmental impact of animal production. This study analyzes high throughput gene expression data from milk samples to determine key genes and biological mechanisms associated to feed efficiency in dairy sheep.A detailed description of the sheep management practices and calculations for the feed efficiency index (FEI) are detailed in 10.3168/jds.2020-19061. For these analyses, we selected animals with divergent FEI values from a group of 40 lactating Assaf ewes. RNA-Seq was performed on milk somatic cell samples from 8 high feed efficiency sheep (H-FE), FEI = −0.29 (SD = 0.23), RFI = −0.16 (SD = 0.25), and 8 low feed efficiency sheep (L-FE), FEI = 0.81 (SD = 0.24), RFI = 0.19 (SD = 0.24)).
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.