Leucometric analysis of 1-day-old chicks inoculated with Salmonella Typhimurium or Lactobacilli

Salmonella infection is responsible for major economic losses in poultry industry. Consequently, the development of new methods for fighting such disease is desirable, such as the use of acid-lactic bacteria. However, reference values of chicks in such conditions are dissimilar to those of other species. Leucometry reference values for chicks have not been reported. The aim of this article was to evaluate and determine the leucometric values of chicks inoculated with Salmonella Typhimurium or treated with Lactobacilli probiotics. In this study, 144 1-day-old birds were divided in three groups of 48 animals each (non-treated group, Salmonella Typhimurium (ST)-inoculated group, and Lactobacilli inoculated group). A total of four blood collections were made with the first one performed 3 h after inoculation with ST or treatment with Lactobacilli. Subsequent samples were obtained every 48 h for 7 days. Leucometric evaluation was performed immediately after each collection. All birds presented an initial decrease pattern in general leukocyte values, and the chicks inoculated with ST revealed lymphomonoheteropaenic leukopaenia, eosinophilia and basophilia in conjunction with convalescence after 96 h of inoculation. The animals inoculated with Lactobacilli revealed leucocytosis with monocytosis, lymphocytosis and marked eosinopaenia. We conclude that there is no efficient bone marrow response in 1-day-old chicks challenged with Salmonella Typhimurium; additionally, an immunostimulatory effect in 1-day-old chicks treated with Lactobacilli-modulated probiotics could be stated. © 2011 Springer-Verlag London Limited.