Effects of two factors，treatment time and withdrawal period，on efficien-cy of clenbuterol for pigs were examined in the experiment with 48 hogs which were dev－ided into 6 groups，The resuIts showed that clenbuterol can improve the growth ratefeed conversion lean meat percentage and fat percentage of the pigs When the pigs weretreated with dietary clenbuterol supple－lnentation for 3－6 weeks and...
