EN
There was evaluated the content of lasalocid in the tissues of lambs which had been given the drug with feedingstuffs at the rate of 50 mg per animal daily. The concentration of the antibiotic in pig tissues was determined directly after slaughter and after 5 and 10 days of the drug withdrawal requirement. The use of the drug to the end of pigs’life resulted in the maintenance of lasalocid in the liver at the level of 17 mcg/kg and in the kidneys and muscles at 5 mcg/kg. Withdrawal of the antibiotic from feedingstuffs for 5 days before slaughter was enough to find no residues in the tissues of pigs. In addition, there was assayed the stability of the drug in tissues stored at from 0°C to 5°C. It was found that the level of lasalocid decreased at half after the first 48 hours and then maintained at the same level. The studies confirmed a high effectiveness of lasalocid as a growth stimulant for lambs.