Precipitins to Micropolyspora faeni in the adult cattle of selected herds in Scotland and north-west England


Dr H. M. Pirie, Department of Veterinary Pathology, University of Glasgow Veterinary School, Bearsden Road, Glasgow G61 1QH.


Sera from all housed adult cattle in twelve herds were examined for precipitating antibody to Micropolyspora faeni at the beginning of winter and approximately 5 months later in the spring; during this time they had been fed hay. Six of these herds were owned by farmers with farmer's lung. The average incidence of precipitins was 33% on the first occasion and 47% on the second occasion. After the winter there was a statistically significant increase in the number of animals with precipitins in five herds. A positive correlation was shown between the incidence of precipitins and age.

None of seventy-five animals on a farm feeding good hay and only one of fifty-eight cattle fed silage had precipitins after the winter. Whereas, on a farm where the farmer complained of a recurrence of the symptoms of farmer's lung when feeding hay, the incidence of precipitins in his cows increased dramatically from 9% to 76%. A farm with a respiratory disease problem in the cattle, diagnosed as bovine farmer's lung, had 83% of its animals positive.

The significance of precipitins and the problem of diagnosing farmer's lung in cattle are discussed.