Mycoplasmaspecies in chicken flocks with different management systems

Abstract

Chicken flocks hatched together but reared under different management systems were examined for mycoplasmas over a two‐year period. On the farm A multiple‐age flocks were reared in close contact. This farm had not been depopulated for over 15 years. On farms B, C and D single‐age flocks were reared and the farms were depopulated every year. On farm A 218 birds from 20 flocks were tested: mycoplasmas were isolated from 202 (92.7%). On farms B, C and D 289 birds from seven flocks were tested: mycoplasmas were recovered from 55 (19.0%). On farm A the following mycoplasmas were identified: M. gallisepticum (46.9% of isolates), M. gallinarum (47.8%), M. pullorum (46.3%), M. gallinaceum (43.2%),M. iners (10.9%), M. iowae (8.3%),M. synoviae (51.7%), M. lipofaciens (23.8%) and M. glycophilum (16.7%). Furthermore, mycoplasma strains which do not belong to recognised species of avian mycoplasmas, Acholeplasma laidlawii and an unidentified Acholeplasma strain were also isolated. On farms B, C and D the isolates were identified as M. gallisepticum or M. synoviae. The only exception was one culture from which M. gallinarum was recovered. The differences between farm A and farms B, C and D regarding total mycoplasma isolation yields and incidence of their species are significant (/K0.01) and are attributed to the different management systems.