Published online by Cambridge University Press: 02 September 2010
A control diet was compared with a diet containing 2 mg diethylstil-boestrol (DES) plus 2 mg methyltestosterone (MT) per kg air-dry feed, the hormone treatment extending either from 20 to 84 kg live weight or from 50 to 84 kg live weight. The experiment contained 20 blocks, each of 3 littermate castrated male pigs individually penned and fed to a restricted scale. Hormone supplementation had no effect on growth performance and significantly affected car-cass characteristics only when given for the longer period. Killing-out percentage, backfat thickness and percentage subcutaneous fat plus skin in the gammon joint were reduced and carcass length, percentage bone and percentage lean in the gammon joint were increased when the supplement was given over the longer period.