Changes made by Commission Directive 87/238/EEC of 1 April 1987 amending the Annexes to Council Directive 74/63/EEC on undesirable substances and products in animal nutrition
EU Directive 1987/238
Made to Council Directive 74/63/EEC of 17 December 1973 on the fixing of maximum permitted levels for undesirable substances and products in feedingstuffs
From legislation.gov.uk's record of changes, the official one: see it there.