Correlation between the natural infection by Corynebacterium pseudotuberculosis in goats and serum progesterone levels and corpus luteum development

Abstract

Caseous Lymphadenitis (CLA) is an infectious disease that affects small ruminants, and the bacterium Corynebacterium pseudotuberculosis is its etiologic agent. This disease presents a high morbidity and a great economic impact on goat farming, leading to reduced milk and meat production and reproductive losses. The available data about the influence of C. pseudotuberculosis on the reproductive system were obtained after experimental inoculations. In this way, this study aimed to evaluate the influence of the natural infection by C. pseudotuberculosis on the luteal function and serum progesterone (P4) levels in goats. Sixteen female goats were diagnosed for the presence of C. pseudotuberculosis specific antibodies and divided into 2 groups: CLA positive and negative animals. They were submitted to estrous synchronization, followed by controlled mating. Corpus luteum and serum levels of P4 were evaluated on the 7th and 20th days after mating (D7 and D20). The ultrasonographic results were not statistically different between the 2 groups, as well as serum P4 levels on D7. However, a significant increase in serum P4 levels on the CLA positive group was identified on D20, along with a significant correlation between C. pseudotuberculosis specific antibody production, and P4 serum levels. The result of this study indicates that the infection by C. pseudotuberculosis may influence the reproductive status of female goats through an enhanced production of progesterone.