The present invention relates to new carbazates of the formula (I) ##STR1## wherein A is C.sub.3 to C.sub.10 alkenyl, C.sub.2 to C.sub.10 haloalkyl, trifluoromethyl, phenyl-C.sub.1 to C.sub.3 alkyl, phenyl-C.sub.2 to C.sub.3 alkenyl, naphthyl-C.sub.1 to C.sub.3 alkyl, C.sub.3 to C.sub.7 cycloalkyl-C.sub.1 to C.sub.3 alkyl, furyl which can be nitro-substituted, diphenyl-hydroxymethyl or indazolyl which can be substituted by one or more C.sub.1 to C.sub.4 alkoxy groups; and R is C.sub.1 to C.sub.4 alkyl, and acid addition salts thereof, a process for the preparation thereof and feed additives comprising the same. The compounds of formula (I) may be used in animal husbandry due to their weight-gain increasing and fodder utilization improving effect.