Influence of metaphylaxis for bovine respiratory disease on host transcriptome responses
Ontology highlight
ABSTRACT: To evaluate how commonly-utilized antimicrobials affect the host transcriptome of commercial beef cattle overtime, we enrolled 105 feedlot beef steers randomly into seven different treatment groups (negative control, tulathromycin, tildipirosin, enrofloxacin, florfenicol, ceftiofur, oxytetracycline) to receive a one-time label dose of a commercial antimicrobial or not (negative control), and collected jugular whole blood into PAXgene RNA blood tubes at six time points: Day 0 (baseline), 3, 7, 14, 21, and 56.
Project description:We profiled blood transcriptomics of 24 beef steers at three important stages (Entry: on arrival at the feedlot; Pulled: when sickness is identified; and Close-out: recovered, healthy cattle at shipping to slaughter) to reveal the key biological functions and regulatory factors of BRD and identify gene markers of BRD for early diagnosis and potentially use in selection.
Project description:The nasopharyngeal microbiota of healthy cattle vs. cattle diagnosed with BRD in a commercial feedlot setting was compared using a high-density 16S rRNA microarray (Phylochip). Nasopharyngeal samples were taken from both groups of animals (n=5) at feedlot entry (day 0) and >60 days later.
Project description:Beef represents a major diet component and source of protein in many countries. With an increment demand for beef, the industry is currently undergoing changes towards natural produced beef. Consumers not only concern about product quality, but also for the well-being of animals. Therefore, the consumption of grass-fed meat is continuously growing. However, the nutritional true differences between feeding systems are still unclear. The aim of this study was to examine latissimus dorsi muscle quality and animal welfare by transcriptome and metabolome profiles, and to identify biological pathways related to the differences between grass- and grain-fed Angus steers. By RNA-Seq analysis of latissimus dorsi muscle, we have recognized 241 differentially expressed genes (FDR < 0.1). The metabolome examination of muscle and blood revealed 163 and 179 altered compounds in each tissue (P-value < 0.05), respectively. Accordingly, alterations in glucose metabolism, divergences in free fatty acids and carnitine conjugated lipid levels, and altered β-oxidation, have been observed. In summary, this study demonstrates a unique transcriptomic and metabolic signature in the muscle of grain and grass finished cattle. Results support the accumulation of anti-inflammatory n3 polyunsaturated fatty acids in grass finished cattle, while higher levels of n6 PUFAs in grain finished animals may promote inflammation and oxidative stress. Furthermore, grass-fed animals produce tender beef with lower total fat and higher omega3/omega6 ratio than grain fed animals, which could potentially benefit consumer health. Finally, blood cortisol levels strongly indicate that grass fed animals experience less stress than the grass fed individuals The steers came from a closed Wye Angus herd with very similar genetics. The grass-fed group was comprised of steers that received alfalfa and orchard grass hay, clover and orchard grass pasture, or orchard grass and alfalfa pasture. The grass-fed individuals consumed grazed alfalfa upon availability and bales during winter and were not exposed to any corn, any form of grain or feed by-products. The alfalfa and grass hay were harvested from land that has had minimal fertilizer and no application of pesticides or inorganic chemicals. The control group was fed a conventional diet consisting of corn silage, soybean, shelled corn and minerals. The pastures were managed as organic landsâwithout fertilizers, pesticides or any chemical additives. At the slaughter plant, 10 ml whole blood sample from the jugular vein was collected in EDTA tubes and directly storage at -80°C. Then, a small piece of longissimus dorsi muscle was obtained from each hot carcass at the level of the 12th intercostal space and immediately frozen in dry ice for posterior analysis.
Project description:Steer small intestine transcriptome Evaluation of the naturally occurring transcriptome variation among beef steers with divergent gain and feed intake phenotypes.
Project description:The transcriptome of 189 samples across four tissues from 48 beef steers with varied feed efficiency were generated using Illumina HiSeq4000
Project description:Steer liver transcriptome Evaluation of the naturally occurring transcriptome variation in liver among beef steers with divergent gain and feed intake phenotypes.
Project description:Steer spleen transcriptome Evaluation of the naturally occurring transcriptome variation in the spleen among beef steers with divergent gain and feed intake phenotypes.
Project description:Steer mesenteric fat transcriptome. Evaluation of the naturally occurring transcriptome variation in mesenteric fat among beef steers with divergent gain and feed intake phenotypes.
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:The biological mechanisms associated with the residual feed intake in ruminants have been harnessed immensely via transcriptome analysis of liver and ruminal epithelium, however, this concept has not been fully explored using whole blood. We applied whole blood transcriptome analysis and gene set enrichment analysis to identify key pathways associated with divergent selection for low or high RFI in beef cattle. A group of 56 crossbred beef steers (average BW = 261.3 ± 18.5 kg) were adapted to a high-forage total mixed ration in a confinement dry lot equipped with GrowSafe intake nodes for period of 49 d to determine their residual feed intake (RFI). After RFI determination, weekly whole blood samples were collected three times from beef steers with the lowest RFI (most efficient; low-RFI; n = 8) and highest RFI (least efficient; high-RFI; n = 8). Prior to RNA extraction, whole blood samples collected were composited for each steer. Sequencing was performed on an Illumina NextSeq2000 equipped with a P3 flow. Gene set enrichment analysis (GSEA) was used to analyze differentially expressed gene sets and pathways between the two groups of steers. Results of GSEA revealed pathways associated with metabolism of proteins, cellular responses to external stimuli, stress, and heat stress were differentially inhibited (false discovery rate (FDR) < 0.05) in high-RFI compared to low-RFI beef cattle, while pathways associated with binding and uptake of ligands by scavenger receptors, scavenging of heme from plasma, and erythrocytes release/take up oxygen were differentially enriched (FDR < 0.05) in high-RFI, relative to low-RFI beef cattle. Taken together, our results revealed that beef steers divergently selected for low or high RFI revealed differential expressions of genes related to protein metabolism and stress responsiveness.