Banca de DEFESA: ALEX LAURINDO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALEX LAURINDO DA SILVA
DATE: 20/02/2025
TIME: 08:30
LOCAL: https://meet.google.com/usg-mbbc-bvn
TITLE:

EFFECT OF VIRULENCE OF DIFFERENT TYPES OF VACCINES AGAINST INFECTIOUS BRONCHITIS STRAIN BR VARIANT IN BROILERS

KEY WORDS:

Chicken; post-vaccination reaction; live vaccine; histomorphometry; histopathology; infectious bronchitis; zootechnical index.

PAGES: 39
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Clínica e Cirurgia Animal
SUMMARY:

Industrial poultry farming is a productive sector that requires reasonable investment, whose return is proportional to the ability of companies to maximize gains and minimize sources of losses. Its growth would not be possible without the adoption of preventive sanitary measures against many pathogens, including those that cause respiratory disorders, such as the bnfecciosa bronchitis virus of chickens. A total of 280 birds (one-day-old chicks) were divided into four experimental groups, containing the same number of animals (70 birds), and housed in two different sheds, under controlled conditions of temperature and light. The experimental groups will be: G1: the birds received the BR variant bronchitis vaccine of the Cevac IBras L® strain; G2: control group, composed of birds in the same housing conditions as G1, but did not receive vaccine; G3: birds received BR variant bronchitis vaccine of the Vaxxon® BR strain; ; G4: control group, composed of birds in the same housing conditions as G3, but did not receive vaccines. The application of the vaccines (G1 and G3) was sprayed. For histomorphometry and histopathology, tracheal fragments were collected, processed and stained with hematoxylin and eosin for observation under an optical microscope. Significant histomorphometric differences (p<0.05) were observed between the vaccines, where the birds from G3 and showed greater thickening of the tracheal mucosa in relation to the birds from G1, at most of the ages evaluated. For the tracheal mucosa thickness variable, the parametric ANOVA - Tukey test was applied. In histopathology, we observed milder lesions in birds vaccinated with the Cevac IBras L® vaccine compared to birds vaccinated with Vaxxon® BR. In the zootechnical analysis, mortality rates, average weight of the birds, total weight gain were evaluated, where the group vaccinated with Cevac IBras L® vaccine showed daily weight gain of 74.63g with total weight gain of 3,552 g per animal, 212 g more than the vaccinated Vaxxon® BR group. There was no statistical difference in the Rstudio test (RStudio R version 4.3.2.), but a numerical and economic difference, if we consider the production cost of R$4.20 kg/bird, we will have a difference of R$0.89 between the group vaccinated with Cevac IBras L® x Vaxxon BR. Infectious bronchitis is a high-impact disease in Brazilian poultry farming, currently strains against variant bronchitis are widely used as a way to protect birds. However, not all strains have the same behavior in relation to protection. We conclude that in this study the Cevac Ibras L vaccine showed less thickening of the tracheal mucosa and consequently less post-vaccination reaction, in addition to better zootechnical results than the Vaxxon® BR vaccine

COMMITTEE MEMBERS:
Presidente - JOAQUIM EVENCIO NETO
Externa à Instituição - MARIA EDNA GOMES DE BARROS - UFRPE
Externa à Instituição - PRISCILLA MARIA CAVALCANTE ROCHA