engleski

Prevalence of Mycoplasma synoviae in layer poultry flocks in Croatia

Mycoplasma synoviae (MS) can cause serious problems on layer farms with drop in egg production and quality of eggs. Statistics confirm that more than 70% of layer farms in Europe are positive for MS. Once positive, flocks have to cope with recurrent problems and continuous losses during all production period together with high investment in treatment. Vaccination showed to be successful in elimination of the MS problem, using different vaccinal strains, but vaccination must be properly done and on time. Despite that, continuous monitoring should be established to determine possible threats for the farm as well as success of vaccination. Since farmers in the last two years continuously reported clinical signs of MS, aim of the study was to determine the prevalence of MS on layer poultry farms in Croatia. Around 300 blood samples from layer flocks were collected during 2017/2018 on 5 large layer farms previously non-vaccinated for MS. Sera were stored on -20°C till analyzed. Level of specific serum antibodies for MS were determined using commercial ELISA kit. Results showed high prevalence of MS on tested farms, especially in the last half a year, with over 80% of positive flocks. Average titres were in range of 2500 to 12 000. On multi-age farms usually younger flocks had lover titres with higher SD, while older flocks had higher average titres with lower SD. There were several cases of acute manifestation with poor egg quality and egg production decrease, what was confirmed by molecular diagnostics, together with simultaneous infection with M. gallisepticum (MG) on one farm. This survey confirms above mentioned statistics of continuous threat to layer egg production from MS and MG as well. This also confirms the need to modify the vaccination program and protect the production using available MS vaccines and to continuously monitor their impact on wild strain presence.

Layer hens, MG, MS, Mycoplasma

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