An evaluation of colostral immunity and the acquired immune response to bovine babesiosis using the complement fixation and the indirect fluorescent antibody tests : a dissertation /
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| Other Authors: | , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[1976]
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| Subjects: |
| Abstract: | ABSTRACT: The complement fixation (CF) and indirect fluorescent antibody (IFA) tests for Babesia bigemina and Babesia argentina were applied to serums collected from 3 experiments. Experiment 1 involved 6 calves infected once with Babesia argentina and 6 calves infected once with Babesia bigemina. In the Babesia argentina infected calves, the CF and IFA titers were positive at the end of one year, and there was only a low level heterologous titer to Babesia bigemina which persisted for 2 to 4 months. In the Babesia bigemina infected calves, homologous CF titers were low and did not persist over 4 months, but heterologous titers to Babesia argentina were higher and persisted for over 7 months. Homologous IFA reactions were of high titer to Babesia bigemina and persisted the entire year; heterologous reactions were of low titer and persisted for only 3 months. In experiment 2, six calves born in an endemic zone of Colombia were continually exposed to natural tick-transmitted infections of Babesia argentina and Babesia bigemina for one year, but they did not develop clinical babesiosis. Serologic titers were positive for both organisms during the first week of life, and protection from the clinical effects of Babesia infections was considered due to protective antibodies in the colostrum. Repeated natural exposure caused fluctuating positive titers during the first year of life. In experiment 3, serums were collected from 5 noninfected calves before ingestion of colostrum from cows with antibody titers to babesiosis, and weekly for 6 months thereafter. Highest CF and IFA titers were measured in the serum of each calf at 1 week of age, intermediate titers were measured in the colostrum itself, and the lowest titers were detected in the serum from each cow. Antibodies persisted for as long as 20 weeks, depending on the original titer. Both the CF and IFA tests were approximately equal in their ability to detect colostral antibodies. The IFA test is recommended as the test of choice for a reliable and sensitive means of obtaining serologic evidence of babesial infection. The CF test, especially for Babesia bigemina, often lacked sensitivity and reliability. |
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| Item Description: | Vita. "Major subject: Veterinary Medical Sciences." "Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of Doctor of Philosophy August 1976". |
| Physical Description: | x, 122 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references (leaves 113-121). |