The prevalence of serum precipitating antibody to Aspergillus fumigatus in adult cattle in Britain

The prevalence of precipitating antibody to A. fumigatus in 3509 sera from adult cattle in 44 herds was 25 per cent. Only 19 per cent of sera from grazing or recently housed animals were positive compared with 30 per cent of those taken towards the end of the winter. Mouldy hay was the most likely source of A. fumigatus antigens although a positive correlation between the prevalence of precipitins and either the mouldiness of the hay or the frequency of coughing in the springtime was not established. However, there was a positive correlation between the age of cattle sampled and the prevalence of antibodies. Mycotic abortion had been confirmed in only one of 6 herds in which more than 80 per cent of the cows were seropositive and so it can be inferred that the presence of serum precipitating antibody is of very little value in the diagnosis of mycotic abortion resulting from A.fumigatus infection.