OBJECTIVE: To measure the prevalence of megabacteria in @entity5798 -breeding colonies and to evaluate possible methods to reduce the prevalence. DESIGN: A monitoring study over several years. SAMPLE POPULATION: Two @entity5798 ( @entity5798 ) colonies with over 300 birds each. PROCEDURE: The prevalence of megabacteria in the faeces in two @entity5798 breeding colonies, colony 1 and 2, was determined by faecal examination of each bird. Following an initial survey (1990), most of the birds that were scored 2+ or more were culled and a management practice was implemented to discriminate against positive birds. Consecutive yearly surveys (1991, 1992) were conducted on the young birds bred in these colonies. The prevalence of megabacteria in colony 2 was also evaluated in 1994 and 1996 after all the birds were treated with @entity2379 administered in drinking water. RESULTS: The prevalence of megabacteria in the two colonies was significantly (P < 0.001) different. Overall the prevalence of megabacteria adjusted for colony differences was significantly higher (P < 0.025) in males compared to females. Age was not an influencing factor. After the initial survey, the prevalence in the offspring did not significantly (P > 0.05) decrease in the following two annual breeding seasons but by inference it did significantly decrease after @entity2379 treatment. CONCLUSION: The practice of culling most birds with more megabacteria in faeces and discriminating against positive birds when selecting birds for breeding or culling birds on show quality does not decrease megabacteria prevalence in the offspring. However, a reduction in prevalence does occur with administration of @entity2379 . Birds may have @entity2379 -resistant organisms and these birds need to be identified and culled.

Prevalence of megabacteria in XXXX colonies.

@entity5798 :: ('13146', 'Species') :: ['Melopsittacus undulatus', 'budgerigar'] @entity2379 :: ('MESH:D000666', 'Chemical') :: ['amphotericin B']
@entity5798 :: (13146,Species) :: ['budgerigar']
