8. Serological evaluation of commmercial vaccines against enterotoxemia in goats

VESCHI J.L.A.; DUTRA I.S.; ALVES M.A.B.; FERNANDEZ MIYAKAWA M.E.; UZAL F.A.

Queretaro, Mexico

Congreso; 9th International Conference on Goats, XXIII Reunión Nacional sobre Caprinocultura; 2008

Enterotoxemia in sheep and in goats is caused by the effects of the epsilon toxin of Clostridiumperfringens type D, being considered the main infectious cause of mortality in those animal species.The main prophylactic measures include adequate nutritional management and vaccination of allanimals using vaccines of high immunogenic power. Six commercial vaccines containing in itsformulation the epsilon toxoid of C. perfringens type D were sorogically evaluated. Eighty four female goat kids, whose mothers had no previous vaccination history against clostridioses were used. They were divided into six groups of 14 animals each. The animals of the control group didn't receive any vaccine dose and the animals from the groups 1 to 5 received two vaccine doses. The first vaccine dose was applied at 45 days of life (day zero) and the second dose at 75 days (30 days after the first dose). Blood samples were collected from the goat kids at the days zero, 30, 60, 90, 120 and 150 after the beginning of the experiment, in order to evaluate the immunologic response. The Indirect ELISA technique was used for the quantification of the antibodies against epsilon toxin in the samples of blood serum of the animals. In day zero, no animal presented titre considered protector. The largest number of animals considered protected was found at day 60, in response to the two initial doses of the vaccine (days 0 and 30, first and second doses, respectively). Only five animals which received the vaccine 1 and one animal which received the vaccine 3 stayed with titres of antibodies considered up to 150 days after the first vaccine dose. Based on the results, it was concluded that the evaluated vaccines showed small amount of epsilon toxoid in the commercial formulations, a crucial fact for the low efficiency of the vaccines. For commercial reasons, the vaccines against the clostridioses present versatile formulations, with several toxoid types, used for various animal species, which certainly contributed to reduce their effectiveness in preventing the illnesses caused by the clostridia or their toxins.