Development of a bacterial-toxoid vaccine to prevent the poor egg-shell quality syndrome in breeder birds and commercial laying hens

• Grant number: 98/14865-1
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: April 01, 1999
• End date: July 31, 2002
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Masaio Mizuno Ishizuka
• Grantee: Masaio Mizuno Ishizuka
• Company: Livet Produtos Veterinários Ltda

Abstract

The present piece of research is intended to continue the study of the poor egg-shell quality of breeder birds, and, in particular, commercial layers in Brazil, in order to develop a bacterial toxoid vaccine to prevent or minimize this problem (stages 1 and 2, respectively, of the action plan). In the light of the substantial economic losses in Brazilian poultry raising, deriving from the poor development of the egg shell (around R$ 79 million in 1996), and the observation that part of the cause of this problem could be connected not just to age, nutrition, genetics, or the environment, but also to the health of the birds - involving specific pathologies, including alteration to the metabolism of intra-medullar calcium, caused by unknown or little-studied infectious agents - Livet Produtos Veterinários has begun a microbiological study of the bone marrow of the femur, tibia and metatarsus of birds with altered egg-shell quality. As a result, it was observed that the change in the calcification of the bone marrow and consequent malformation of the egg-shell may be related to the bacterial etiology including its respective toxins. Field experiments have enabled the identification of bacteria such as S. epidermides, S. aureus, Haemophylus sp., Streptococcus sp., E. coli and Bacilus sp. in the birds’ bone marrow without creating a problem for the egg-shells in the same breeding stock and the preparation of an experimental vaccine based only on the S. aureus. Vaccinated and non-vaccinated birds show a relationship between the presence of the bacteria and the re-absorption of calcium into the bone marrow. (AU)