Project description:The hypothesis tested was that the uterine environment of lactating cows would affect conceptus gene expression. Approximately 65-75 days post-partum (dpp) the estrous cycles of non-lactating (dried off immediately post partum: n=12) and lactating (n=13) cows were synchronized and on Day 7 a high quality blastocyst derived from superovulated heifers was transferred. A control group of maiden heifers (n=8) were synchronized, inseminated to a standing heat and slaughtered on the same day as non-lactating and lactating recipients (Day 19; estrus=Day 0). The ipsilateral uterine horn was flushed with 10 ml PBS and the conceptus, when present, and uterine luminal fluid (ULF) snap frozen in liquid nitrogen prior to analysis. Gene expression analysis of the conceptus was performed by RNA sequencing analysis while amino acid (aa) composition of ULF was determined by High Performance Liquid Chromatography (HPLC). Eight differentially expressed genes (DEGs) were identified between conceptuses recovered from non-lactating cows versus heifers while 269 DEGs (100 up-regulated and 169 down-regulated) were identified between conceptuses recovered from lactating cows compared to heifers. The aa, alanine, glycine, serine and threonine, arginine, leucine and valine, were significantly lower in abundance in ULF recovered from heifers compared to both non-lactating or lactating cows. Glutamic acid, glutamine and lysine concentrations were lowest in heifers compared to both cow groups. This study demonstrates that exposure of a grade one embryo to a uterine environment that has been exposed to the metabolic stresses associated with lactation modifies the transcriptome of the conceptus and aa composition of the ULF.
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:Infertility in lactating dairy cows is explained partially by the metabolic state associated with high milk production. The hypothesis was that lactating and non-lactating cows would differ in endometrial and placental transcriptomes during early pregnancy (day 28 to 42) and this difference would explain the predisposition for lactating cows to have embryonic loss at that time. Cows were either milked or not milked after calving. Reproductive [endometrium (caruncular and intercarunclar) and placenta] and liver tissues were collected on day 28, 35, and 42 of pregnancy. The primary hypothesis was rejected because no effect of lactation on mRNA abundance within reproductive tissues was found. Large differences within liver demonstrated the utility of the model to test an effect of lactation on tissue gene expression. Major changes in gene expression in reproductive tissues across time were found. Greater activation of the transcriptome for the recruitment and activation of macrophages was found in the endometrium and placenta. Changes in glucose metabolism between day 28 and 42 included greater mRNA abundance of rate-limiting genes for gluconeogenesis in intercaruncular endometrium and evidence for the establishment of aerobic glycolysis (Warburg effect) in the placenta. Temporal changes were predicted to be controlled by CSF1, PDGFB, and JUN. Production of nitric oxide and reactive oxygen species by macrophages was a mechanism to promote angiogenesis in the endometrium. Reported differences in pregnancy development for lactating versus non-lactating cows could be explained by systemic glucose availability to the conceptus and appear to be independent of the endometrial and placental transcriptomes.
2017-08-10 | GSE94794 | GEO
Project description:Highly Pathogenic Avian Influenza A virus subtype H5N1 (clade 2.3.4.4b) Isolated from a natural protected area in Peru
Project description:Transcriptional profiling of bovine in-vitro produced blastocysts at day 7 and granulosa cells collected at day 8 to 11 post-eostrus of lactating cows.
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.
Project description:Lactating cows experience transient metabolic stresses during postpartum which results in abnormal concentrations of non-esterified fatty acids and beta-hydroxybutyrate that can affect embryo-maternal communication and ultimately reproductive success. We hypothesize that metabolic challenges in lactating cows influence DNA methylation changes of the embryos prior to implantation affecting genes involved in embryo developmental competency. Therefore, we compared whole genome bisulfite sequencing (wgbs) of morulas derived from in vitro produced 2-4 cell embryos and transferred in the oviduct of metabolically profiled lactating cows until day 7. Similar stage of in vitro production (IVP) embryos were transferred to the oviduct of nulliparous heifers as a metabolically unchallenged control. Bisulfite-Seq DNA libraries were generated from groups of five morulas using an EZ DNA methylation-direct kit and Pico-Methyl seq library preparation kit (Zymo Research), and parallel sequenced using the illumine HiSeq2500 system at the institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.