Project description:The study investigated gene expression patterns in liver tissue to understand the biological functions of genes that are potentially involved in controlling / regulating feed efficiency in Nordic dairy cattle.
Project description:We functionally analyzed the rumen epithelial transcriptomes from low- and high- feed efficient beef steers to identify differences that might contribute to variation in feed efficiency.
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: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 the livestock industry, feed is the largest expense, driving interest in breeding more feed-efficient animals. Residual feed intake (RFI) is a widely used measure of feed efficiency, accounting for actual feed intake versus expected requirements for maintenance and production. Because feed efficiency is highly polygenic, associated genes may have pleiotropic effects on traits such as immunity, complicating breeding strategies. One way to study pleiotropy is through -OMICs technologies, including transcriptomics, which uses RNA-Sequencing (RNA-Seq) to analyze the transcriptome at specific tissue levels and time points. This study used RNA-Seq to identify differentially expressed (DE) genes between Low RFI (n = 22) and High RFI (n = 17) Holstein cows. A total of 36 genes were DE between groups, enriched in 28 metabolic pathways (FDR < 0.01), most of which were immune-related, including the RIG-I-like receptor signaling pathway. QTL annotation and enrichment analyses were also performed for the DE genes. Within these gene regions, 646 previously annotated QTL were identified, of which 26.7% were related to milk traits. Notably, 10 QTL were associated with feed efficiency, while 4 were linked to host immunity. QTL enrichment further revealed 387 significantly enriched QTL, with the majority of the top associations related to health. In summary, this research identified candidate genes and QTL regions suggesting potential pleiotropic relationships between feed efficiency and immunity in Holstein dairy cows. These findings highlight the need for further investigation to balance productivity and health in genetic improvement programs.
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.
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 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.
2018-06-21 | GSE116058 | GEO
Project description:Feed microbiota and Nordic Red dairy cows rumen bacteria
Project description:RNA sequencing (RNA-Seq) was performed on rumen papillae from 16 steers with variation in gain and feed intake. Sixteen rumen papillae samples were sequenced by Cofactor Genomics (St.Louis, MO).