Project description:We investigated the effects of wood kraft pulp (WP) supplementation on ruminal pH, fermentation, and epithelial transcriptomic dynamics in Holstein cattle during the high-grain diet challenge.
Project description:Cattle are often fed high concentrate diets to increase energy intake and improve overall animal performance. Such diets also cause changes in fermentation patterns and epithelial function. However, the molecular mechanisms involved in regulating epithelial function for cattle fed high concentrate diets have not been elucidated. In this study, we aimed to gain a broad overview of the involved molecular mechanisms by detecting differentially expressed genes (DEG) in rumen tissue from dairy cows fed a low concentrate (LC; 8%) compared to a high concentrate (HC; 64%) diet using a bovine-specific microarray platform containing 16,846 unique gene loci and 5,943 ESTs from the bovine genome. Feeding the HC diet increased the total volatile fatty acid concentration and markedly reduced ruminal pH, suggesting that the dietary treatments used did induce changes in ruminal fermentation. In response to changes in the ruminal environment, a total of 5,200 elements were detected as DEG in ruminal tissue with >1.5-fold expression change (P < 0.05) for cows fed HC relative to LC. Of the 5,200 DEG, 2,233 and 2,967 were up- and down-regulated, respectively. The GENECODIS analysis elucidated that relationships among the DEG represented 19 annotations characterized with GO molecular function and KEGG pathways with 26 DEG identified in multiple annotations such as calcium signaling and gap junction pathways. Among those DEG that were identified numerous times, catalytic subunit of cAMP-dependent protein kinase (PRKACB) was down-regulated in ruminal tissue from cows fed HC, suggesting that this gene may have important roles including regulation of cell proliferation and differentiation, and intracellular pH regulation. Two-condition experiment, High concentrate vs. Low concentrate diets. Biological replicates: 5 high concentrate fed, 5 low concentrate, independently grown and harvested. Two replicates per array.
Project description:Milk compounds are important for human nutrient requirements and health. The ruminal metabolic profile is responsible for dietary nutrition and determines milk production. Perilla frutescens leaf (PFL) is a commonly used medicinal herb due to its bioactive metabolites. This study elucidated the effects of PFL on the metabolome of two biofluids (rumen fluid and milk) of 14 cows fed a basic total mixed ration diet (CON, n = 7) and supplemented with 300 g/d PFL per cow (PFL, n = 7) by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Milk PE-NMe (18:1(9Z)/18:1(9Z)) and DG (18:0/20:4(5Z,8Z,11Z,14Z)/0:0), oleanolic acid, and nucleotides were upregulated, and milk medium-chain fatty acids (2-hydroxycaprylic acid) and isoflavones (daidzin, ononin) were down-regulated in response to PFL. The supplementation of PFL increased the abundance of pyrimidine nucleotides both in rumen fluid and milk. The pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids were enriched both in the rumen fluid and milk. We also found the milk 2-hydroxycaprylic acid was positively correlated with ruminal uridine 5-monophosphate, and was negatively correlated with ruminal deoxycytidine, and the milk thymidine was positively correlated with ruminal icosenoic acid. This study found that the supplementation of PFL could alter the ruminal metabolic profiles and milk synthesis through regulation of the pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids. Our new findings provide comprehensive insights into the metabolomics profile of rumen fluid and milk, supporting the potential production of Perilla frutescens milk in dairy cows.
Project description:Beef represents a major diet component and one of the major sources of protein in human. The beef industry in the United States is currently undergoing changes and is facing increased demands especially for natural grass-fed beef. The grass-fed beef obtained their nutrients directly from pastures, which contained limited assimilable energy but abundant amount of fiber. On the contrary, the grain-fed steers received a grain-based regime that served as an efficient source of high-digestible energy. Lately, ruminant animals have been accused to be a substantial contributor for the green house effect. Therefore, the concerns from environmentalism, animal welfare and public health have driven consumers to choose grass-fed beef. Rumen is one of the key workshops to digest forage constituting a critical step to supply enough nutrients for animals’ growth and production. We hypothesize that rumen may function differently in grass- and grain-fed regimes. The objective of this study was to find the differentially expressed genes in the ruminal wall of grass-fed and grain-fed steers, and then explore the potential biopathways. In this study, the RNA Sequencing (RNA-Seq) method was used to measure the gene expression level in the ruminal wall. The total number of reads per sample ranged from 24,697,373 to 36,714,704. The analysis detected 342 differentially expressed genes between ruminal wall samples of animals raised under different regimens. The Fisher’s exact test performed in the Ingenuity Pathway Analysis (IPA) software found 16 significant molecular networks. Additionally, 13 significantly enriched pathways were identified, most of which were related to cell development and biosynthesis. Our analysis demonstrated that most of the pathways enriched with the differentially expressed genes were related to cell development and biosynthesis. Our results provided valuable insights into the molecular mechanisms resulting in the phenotype difference between grass-fed and grain-fed cattle. Ruminal wall samples from two randomly chosen animals per group were obtained, totaling four samples. The animals were born, raised and maintained at the Wye Angus farm. This herd, which has been closed for almost 75 years and yielded genetically similar progenies, constitutes an excellent resource to perform transcriptomic analysis. The genetic resemblance among individuals permits us to better control the cause of variation between experimental clusters and individuals. The randomly chosen pairs of animals were part of larger sets of steers that received a particular treatment. All animals received the same diet until weaning. The grain group received conventional diet consisting of corn silage, shelled corn, soy bean and trace minerals. The grass fed steers consumed normally grazed alfalfa; during wintertime, bailage was utilized. The alfalfa has been harvested from land without any fertilizers, pesticides or other chemicals. The steers ate no animal, agricultural or industrial byproducts and never receive any type of grain. Then, the calves were randomly assigned to one diet and exclusively received that regimen until termination. Grain–fed animals reached the market weight around the age of 14 month-old, however, grass-fed steers required approximately 200 additional days to achieve the same weight. Immediately after termination at the Old Line Custom Meat Company (Baltimore, MD) a small piece of ruminal wall was excised, cleaned and preserved at -80°C for posterior processing.
Project description:We explored the effect of long-term high-concentrate diet feeding on ruminal pH and fermentation, and its effect on the rumen epithelial transcriptomes in Japanese Black beef cattle during a 20-month fattening period.
Project description:Fifiteen male Hu-lambs were randomly assigned to three groups (n = 5 for each group). Lambs in the control (CON), HG, and HP groups received low-grain nonpelleted diet (30% concentrate), HG diet (70% concentrate), and HP diet containing the same ingredients and nutritions with HG group, respectivley. After 60-day treatment, all the lambs were slaughtered to collect ruminal epihelium samples for transcriptome analysis.