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Full-Text Articles in Life Sciences
Investigation Of Bacterial Taxa As Biomarkers Of Fescue Toxicosis And Heat Stress In Grazing Beef Cows, Sarah Katherine Chewning
Investigation Of Bacterial Taxa As Biomarkers Of Fescue Toxicosis And Heat Stress In Grazing Beef Cows, Sarah Katherine Chewning
Graduate Theses and Dissertations
Fescue toxicosis in grazing beef cattle is caused by consumption of Ergot alkaloids associated with tall fescue (toxic fescue) and is responsible for substantial economic loss to the U.S. beef industry. Cattle consuming toxic fescue suffer adverse physiological responses, such as: hyperthermia, increased respiration rate (RR), poor reproduction and growth performance. Other adverse responses to fescue toxins include the retention of a winter hair coat and vasoconstriction in the extremities, which can lead to tissue necrosis. Identifying cattle with reduced susceptibility to fescue toxins would allow for efficient use of fescue pastures; thus, the objectives of this thesis was to: …
Effects Of Ergot Alkaloids And Bovine Bodily Fluids On Cytochrome P450 Activity, Nicholas Scott Ezell
Effects Of Ergot Alkaloids And Bovine Bodily Fluids On Cytochrome P450 Activity, Nicholas Scott Ezell
Graduate Theses and Dissertations
This thesis evaluates the PromegaTM P450-Glo assay (PromegaTM V9800) as a tool for quantifying ergot alkaloid concentration. Current techniques used for detection of ergot alkaloids are slow and expensive, do not detect all ergot alkaloids, or are not effective on bovine bodily fluids. The first study was conducted to determine effects of commercial ergot alkaloids (n = 6; 0 - 400 μM) on the PromegaTM P450-Glo assay. Cytochrome P450 (CYP450) activity in assay had a differential response to each ergot alkaloid and concentration. As concentrations of ergotamine, dihydroergotamine, ergocornine, and ergocryptine increased CYP450 activity was inhibited (P …
Relationship Of Lactate Dehydrogenase & Prolactin Genotypes To Immune Function, Growth, And Composition Of Replacement Heifers Grazing Tall Fescue, Christina Marie Turner
Relationship Of Lactate Dehydrogenase & Prolactin Genotypes To Immune Function, Growth, And Composition Of Replacement Heifers Grazing Tall Fescue, Christina Marie Turner
Graduate Theses and Dissertations
Objectives of this research were to determine effects of LDH enzymatic activity and circulating PRL on immune response, growth, composition, and reproduction, and to determine the effects of single nucleotide polymorphisms of LDH and PRL on immune function, growth and carcass traits, cyclicty, and fecundity of replacement heifers grazing endophyte infected tall fescue. Eighty-nine Angus based heifers had physical and ultrasound measurements along with blood samples collected at weaning, yearling, and prebreeding. Estrus detection was conducted for 10 d post each collection period, except prebreeding. Pregnancy status was verified after AI and again after bull removal. Heifers were maintained on …
Maternal Environment And Fescue Cultivar Effects On Growth, Development, And Fertility Of Beef Heifers, Jennifer Denyse Patterson
Maternal Environment And Fescue Cultivar Effects On Growth, Development, And Fertility Of Beef Heifers, Jennifer Denyse Patterson
Graduate Theses and Dissertations
Eighty Brahman-influenced cows (5.6 BCS) were assigned to graze common bermudagrass (CB) or toxic tall fescue (E+) during a 60-d breeding season. Body condition (BC) was assessed at d 0, 30, and 60 of breeding season. Cows were managed to achieve marginal (4.2 BCS) or good (6.3 BCS) BC during last trimester. Heifer birth and weaning (WW; 7 to 8 mo) weights were recorded. The Angus sired heifers were weighed and randomly assigned to E+ or non-toxic (Novel) tall fescue at 9 to 10 mo of age for 190d. Heifer weight, growth data, and antral follicle count (AFC) were collected …