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dc.contributor.advisorPalmer,Colinen_US
dc.creatorGhasemi, Farhaden_US
dc.date.accessioned2011-08-27T21:02:19Zen_US
dc.date.accessioned2013-01-04T04:55:01Z
dc.date.available2012-09-09T08:00:00Zen_US
dc.date.available2013-01-04T04:55:01Z
dc.date.created2011-08-27en_US
dc.date.issued2011-09en_US
dc.date.submitted2011-08en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-08272011-210219en_US
dc.description.abstractTwo experiments were designed to study endometritis in postpartum dairy cows. In the first experiment, 30 cows 28 to 41 days in milk (DIM) and without evidence of clinical endometritis were sampled using cytobrush cytology. Cytobrush sampling provided sufficient endometrial material to prepare cytologic specimens and to extract endometrial mRNA. Pro-inflammatory cytokines were analyzed in harvested endometrial tissue taken from cows with and without endometritis. Cytokine expression varied between experimental groups with 30-fold higher IL-6 expression levels (P=0.01), greater than 50-fold higher IL-8 expression levels (P=0.0001), and 20-fold higher TNF-&#945; expression levels (P=0.001) in endometritis-positive versus negative cows. Regression analysis of cytokine expression levels (Ct) and the percentage of PMNs in subclinical endometritis-positive cows showed that for each additional threshold cycle required for IL-8 detection, which corresponded to two-fold less mRNA, the percentage of PMN decreased by 3.3% (P=0.00001). Similarly, for each additional threshold cycle required to detect IL-6 and TNF-&#945;, the percentage of PMNs in endometritis-positive cows decreased by 2.3% (P=0.015) and 2.4% (P=0.054), respectively. Cows with > 18% PMNs required significantly fewer amplification cycles to detect IL-6 (P = 0.01), IL-8 (P =0.0001) and TNF-&#945; (P=0.053) mRNA than cows with 15%) cows in this study were defined as those with the lowest percentage of PMNs that was associated with a significant positive treatment effect. Treated cows with >15% PMNs required 31 fewer days (P=0.041) to become pregnant and had 2.5 times fewer services per conception (P=0.0001) than untreated cows with >15% PMNs. The likelihood of there being CLs at the time of examination in cows with >15% PMNs in endometrial cytobrush cytology was 2.3 times significantly higher (P=0.04). The treatment of cows with ultrasonographically detectable fluid in the uterine lumen with benzathine cephapirin had no effect on days open compared to treatment of cows without fluid in the uterus (P=0.39). Cervical diameter and endometrial thicknesses did not differ between groups of cows with >, < 15%PMNs (P=0.46, P=0.36, respectively). In summary, based on the response to a single treatment with benzathine cephapirin, and the analysis of pro-inflammatory cytokine gene expression, we recommend that a threshold of >18% PMNs be used to define endometritis-positive disease status in cows 28 to 41 DIM. Cervical diameter, ultrasonographic evidence of uterine fluid and ultrasonographic measurement of endometrial thickness were not useful for diagnosing benzathine cephapirin responsive endometritis.en_US
dc.language.isoen_USen_US
dc.subjectCytokinesen_US
dc.subjectDairy cowsen_US
dc.subjectBenzathine cephapirinen_US
dc.subjectEndometritisen_US
dc.titleCharacterization of endometritis in postpartum dairy cowsen_US
thesis.degree.departmentLarge Animal Clinical Sciencesen_US
thesis.degree.disciplineLarge Animal Clinical Sciencesen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US


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