Sub-products as well as edible waste deriving from the production and marketing of agricultural and food products may be destined to animal feeding. Nevertheless, such products and materials cannot be excluded a priori from the definition of "waste" given by Legislative Decree No. 22 of 5 February 1997. Therefore, such materials may be used as feedingstuffs provided that all hygienic and health requirements are fulfilled and the authorization required by article 5 of Act No. 281 of 1963 is grant