The compounds: 4,5,6,7-tetrahydro-7-oxobenzo[]-thien-4-ylurea of formula (I) and 1,2,3,4-tetrahydro-4-oxo1-naphthylurea of formula (II): ##STR6## wherein R' and R are substituents, such as hydrogen, alkoxy, alkyl and benzyl are useful and valuable animal growth-promoting agents.