New cases are now extremely rare, after being at a high frequency just a few decades ago. L Labile Chemically unstable. Lairage Shed or outdoor enclosure for the temporary housing of animals, for example on the way to market, or when they are being transported for export. Lamming Committee Expert Group on Animal Feedingstuffs. Lasswade The CVL's Veterinary Laboratory near Edinburgh.
Lateral transmission See horizontal transmission .
LD 50 See median lethal dose . The pattern of brain tissue damage, used as a distinguishing feature for different TSEs . An essential amino acid . Lipid A substance, containing long chains of fatty acids, which is insoluble in water, but soluble in fat solvents such as alcohol and ether. The Cabinet Minister presiding at the Privy Council, who may also perform ministerial or other duties at the behest of the Prime Minister.