ABSTRACT
During the period from July 1977 to June 1985, specimens from 766 replacement layer and breeder chicken flocks were submitted to the Veterinary Research Institute, Victoria, Australia, for investigation of morbidity, mortality and, or, poor performance. A total of 5940 necropsies, as well as numerous ancillary tests, were performed. The findings for these flocks are presented and the consequences of some particular diseases noted.
Subject(s)
Chickens , Poultry Diseases/epidemiology , Animals , Australia , Dinitolmide/adverse effects , Female , Monensin/poisoning , Nitrofurans/poisoning , Poultry Diseases/drug therapy , Poultry Diseases/mortality , Sulfaquinoxaline/adverse effectsABSTRACT
Utility pigeons on 3 farms were affected by a severe neurological disturbance manifested by fine tremors, rolling gait and incoordination. Affected birds had necrosis of the Purkinje cells of the cerebellar cortex. The birds from the 3 farms had been fed a pelleted diet obtained from a single mix of feed prepared by a stockfeed manufacturer. When feed obtained from the farms was given to utility pigeons under controlled conditions at the laboratory, they suffered the same clinical signs and lesions as seen in birds from the farms. Cross-bred cockerels were not affected when given this feed from day-old to 6 weeks of age. Samples of the feed contained 185 to 226 ppm of the coccidiostat dinitolmide. Utility pigeons given a prepared diet containing a similar level (234 ppm) of dinitolmide developed an identical condition after 3 to 4 weeks feeding. Laying hens were not affected by this feed. Dimetridazole, which was also present in some of the original feed samples, did not exacerbate the condition when included in the diet at a rate of 233 ppm. Production of squabs from the affected farms was dramatically reduced, and many of the breeder had to be culled because of the long-standing neurological disease.
