Evaluation of the effectiveness and safety of a genetically modified live vaccine in broilers challenged with Salmonella Heidelberg.

Evaluation of the effectiveness and safety of a genetically modified live vaccine in broilers challenged with Salmonella Heidelberg. Avian Pathol. 2017 Jun 29;:1-28 Authors: Muniz EC, Verdi R, Leão JA, Back A, Nascimento VPD Abstract Salmonellosis ranks among the major diseases of commercial poultry, and its presence in poultry flocks is responsible for economic losses and risks related to public health. Vaccines are an important tool within integrated programs to control salmonellosis. The purpose of this study was to assess cross-protection provided by the Poulvac(®) ST vaccine in the control of Salmonella Heidelberg (SH) in experimentally challenged 3- and 21-day-old birds. Eighty birds were identified and separated into four treatments (T1: vaccinated and challenged at 3 days of age, T2: unvaccinated and challenged at 3 days of age, T3: vaccinated and challenged at 21 days of age, and T4: unvaccinated and challenged at 21 days of age). The inoculum was produced from a Brazilian field strain of SH. At the end of the experiment, cecum and liver/spleen samples were collected for quantitative and qualitative analysis of SH, respectively. Analysis of the liver/spleen showed that Poulvac(®) ST significantly (p ≤.05) reduced the percentage of SH positivity in the group challenged at 3 days of age, while in the group challenged at 21 days this difference was almost considered significant (p = .0533). On the other hand, there was no ...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research