The Agency is concerned about continuing breaches of these controls. The likelihood that the two animals had BSE is low. The parts of an animal most likely to contain BSE infectivity are removed at the abattoir, as was the case with these animals. One animal, aged 15 months, was slaughtered in December 2001 and put into the food chain. None of the meat is now left. The other, aged 26 months, was slaughtered in January and some of the meat has entered the food chain. The Agency has asked DEFRA for the remainder of the meat to be seized and destroyed.
The Specified Risk Material (SRM) controls and the over thirty month (OTM) rule are the most important consumer protection controls in force. SRM controls are designed to prevent the parts of slaughtered animals most likely to contain the BSE agent from entering the food and animal feed chain. Experts estimate SRM controls remove 95% of the infectivity from affected cattle.
The OTM rule was set by SEAC, the Spongiform Encephalopathy Advisory Committee, in 1996. The European Scientific Steering Committee has since considered data from on-going experimental studies of the pathogenesis of experimental BSE in cattle. They have concluded, from this data, that the earliest time that infectivity is likely to be detected is at about two thirds of the way through the incubation period, This means that infectivity is highly unlikely to arise in cattle under 30 months.
Transmission of BSE: the Agency's review of BSE controls in December 2000 emphasised the uncertainty surrounding the transmission of BSE and said: "knowledge about its (BSE) routes of transmission within the cattle population is incomplete". There have been estimates that maternal transmission could occur in up to 10% of pregnancies, although that is under review and may be revised downwards.
These are the second and third such cases this year, following the disclosure on 14th January 2002 of the 29-month old offspring of a cow with BSE having been slaughtered in an abattoir in Wales.