Bovine mastitis is the most important economic disease to the dairy industry with losses estimated at 2 billion dollars per year in the United States. Staphylococcus aureus (.§.. aureus) is the primary cause of contagious mastitis. Conventional culture methods (National Mastitis Council) were used as a basis for comparing the ability of the enzyme linked immunosorbent assay. ProStaph Iâ ¢, to identify s. aureus. The test had an accuracy of 96%, with a sensitivity of 90% and a specificity of 97%. Results indicated that rinsing teat-cup liners with a 25 ppm iodophor or 100 ppm chlorine solution reduced the presence of S. aureus on the liners by 97%. ProStaph I was used to rapidly screen DHIA preserved milk samples in 10 Virginia cooperator herds. Herds were classified as high (>10% infected) or low prevalence (<10% infected). There were six high prevalence herds after the first test. Average prevalence of cows scoring Ab +2 and +3 was 11.9% ± 7.9. Over the seven month study, prevalence of positive cows declined significantly (P<.OI), but somatic cell count remained relatively unchanged (P>.lO). Four herds continued to have >10% of the animals infected. Incidence of new infection averaged 3.6% ± 2.8 from the first to the last test. Chronic cows averaged 6.9% ± 4.8 over the seven month study. Analysis of variance showed significant (P<.Ol) effects of herd on ProStaph I score J milk yield, and see. Elevated ProStaph I scores were highly correlated (P <.01) with increases in lactation number. ProStaph I changed quadratically (P<.Ol) with increasing SCC. Somatic cell count increased (P<.OI) as ProStaph I score increased. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/42101 |
| Date | 14 April 2009 |
| Creators | Grove, Tina Moler |
| Contributors | Dairy Science, Jones, Gerald M., Barnes, Michael A., Bishop, J. Russell, Vinson, William E. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | x, 77 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 23116663, LD5655.V855_1990.G775.pdf |
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