§ Mr. Martyn JonesTo ask the minister of Agriculture, Fisheries and Food what evidence her Department has of increased severity of symptoms induced by bovine immunodeficiency virus in non-experimental infections or of a syndrome of superinfection.
§ Mr. SoamesDisease induced by bovine immunodeficiency virus in non-experimental cattle has not been diagnosed in this country. Extremely detailed investigations are in progress in a herd in Cheshire in which cattle with serological evidence of exposure to the virus have been identified. We are not aware of any published reports from abroad of disease in non-experimental cattle definitely induced by BIV. The three cattle in the United States from which the virus has been isolated over a period of 25 years were in poor condition but it is not known what role, if any, BIV played. A recent Canadian paper on a serological survey in Ontario dairy cattle reported that positive BIV serological herd test results were associated with slightly lower than average milk production. A published summary of work carried out by Louisiana State university school of veterinary medicine suggested findings of a range of conditions in a single dairy herd where there was also serological evidence of BIV and of the virus which causes enzootic bovine leukosis.