Selenium-responsive myopathy in broiler breeder hens in Queensland

A syndrome characterised by bilateral paralysis and associated with degenerative changes in skeletal musculature, has been noted in adult breeder hens, and their progeny broilers, in a commercial poultry organisation in Queensland. Paralysis occurred between the ages of 24 to 63 weeks in broiler breeder hens and at approximately 6 weeks in the broiler chickens. Onset is slow, taking up to 2-3 days from the time leg weakness if first noticed until paralysis was complete. Other than the paralysis the birds appeared normal. Histopathological and experimental observations indicate that the muscular dystrophy is caused by a selenium deficiency. Supplementation of the diet with selenium at a level of 0.1 ppm completely alleviated the symptoms such that the birds may be returned to the mating pens.