Evaluación de tres protocolos de vacunación de explotaciones de pollo de engorda en el antiplano mexicano, mediante detección de anticuerpos y protección ante un desafío controlado con el virus de bronquitis infecciosa

Abstract

SEROCONVERSION AS THE VACCINATION AND THE PROTECTION TO THE CALLENGE AGAINST INFECTIOUS BRONCHITIS VIRUS WAS DETRMINED IN THIRTY PETERSON X AVIAN FARM BROILERS, BOTH SEXES WIHICH. WERE VACCINATED AT 23 DAYS (GROUP C) WITH AN ATTENUATED VACCINE, AND ANTIBODY TITERS WERE OBTAINED BY THE ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) INDIRECT TECHNIQUE THREE WEEKS AFTER PRIME VACCINATION. CHICKEN THEREAFTER, WERE EXPOSED TO A CHALLENGE WITH THE MASSACHUSETTS 41 VIRUS STRAIN AS A POTENCY TEST. THIRTY BROILERS SERVED AS THE NON VACCINATED CONTROL GROUP. RESULTS OF THE VIRUS ISOLATION INDICATED THAT BROILERS VACCINATED AT ONE-DAY OLD, WITH HALF A DOSE, VIA SPRAY AND REVACCINATED AT AGE 23 DAYS OLD WITH THE COMPLETE DOSE IN THE DRINKING WATER (GROUP C) PRESENTED AN 100% PROTECTION. ANOTHER GROUP (B) VACCINATED AT ONE-DAY OF AGE WITH ONLY A HALF DOSE IN THE DRINKING WATER, PRESENTED AN 82%. THIS PROTECTION, CAN BE CONSIDERED TO BE SATISFACTORY. A THIRD GROUP (A) WAS VACCINATED AT ONE-DAY OLD WITH HALF DOSE BY THIN DROP SPRAY, AND PRESENTED ONLY AN 8.2%, CONSIDERED TO BE AS NOT SATISFACTORY. THE GEOMETRIC MEAN (TGM) VALUE OF ELISA ANTIBODIES IN GROUPS B AND C DID NOT SHOW RELATION WITH THE PROTECTION AGAINST THE CHALLENGE. RESULTS SUGGEST THAT THE VACCINATION PROCEDURE IN GROUP A WAS NOT EFFECTIVE AND DID NOT PROVIDE PROTECTION AGAINST INFECTIOUS BRONCHITIS VIRUS CHALLENGE PERFORMED AT SIX WEEKS OLD.