The response to repeat Zeranol implantation assessed in terms of LWG was evaluated under grazing conditions in both entire and castrated male kids, in order to determine wether the use of the anabolic was of economical importance under the system most widely used for goat meat production.

Forty five Spanish Granedine male kids aged 2 weeks were randomly divided in 3 groups. Group A remained as control, Groups B and C were implanted on weeks 0, 8 and 16 of the 24 week trial with 12 mg. of Zeranol and Group C was also castrated at the begining of this experiment.

The kids remained with their mothers on a Star grass plot for the first implantation period, afterwards they were weaned and their feeding depended only on grass pluss salt and minerals.

To avoid coccidiosis outbreaks the kids were given Amprolvet Super on a 0.006 concentration in the drinking water all through the trial. The animals were weighted fornightly.after a 18 hour fasting period.