Reproductive and systemic lysozyme activities in chicken during experimental Salmonella Gallinarum infection: a comparative analysis between various egg-laying phases

Despite scientific advancement made in poultry farming, the problem of fowl typhoid is still persistent, discouraging significantly the economic prospects of poultry industry. New vaccines and vaccination approaches could make cost effective differences in control of such unbridled infection. Mucosal vaccination in the reproductive tract can stimulate protective localized innate immune response against fowl typhoid. The objective of the study was to investigate induction and dynamics of lysozyme activity within reproductive tract and systemic) circulation following experimental infection with Salmonella Gallinarum at various phases of egg laying viz., pre-egg laying (17–18 weeks), onset of egg-laying phase (19–20 weeks), and peak egg-laying phase (23–24 weeks). Chickens were either infected via intravenous or intravaginal route with10 7 CFU −1 ml of Salmonella Gallinarum. Lysozyme activity was assessed by turbidimetric method employing suspension of Micrococcus lysodeikticus . Lysozyme activity increased during egg-laying phases (both at onset and peak egg-laying phase) and was high in reproductive wash following infection. Serum lysozyme activity was not significantly different between intravenously and intravaginally infected birds. Day 7 post-infection in each trial appeared to be crucial point for intravenously infected birds, where lysozyme activity in both the bodily secretions reduced to their lowest level.The maximum activity was noted during onset of egg laying with pronounced levels in intravaginal inoculates. Immune elicitation in reproductive tract is possible and can be enhanced by injecting suitable antigen amidst different egg-laying phases including S . Gallinarum infections.