[Toxicological studies of Bulgarian activated bentonite]

We studied the endurance of calves, lambs and pigs as well as the acute, subchronic and chronic toxicity for chickens with regard to bentonite of local origin, extra activated in a physico-chemical way. It was proved that the medicine was rather endurable with calves, lambs and pigs without causing intoxication or death after a single internal introduction in doses respectively 4138, 4130 and 1860 mg/kg t. LD0 of the activated bentonite for the chickens in the case of intra-crop application was over 18000 mg/kg t. During a 33-day extra addition to the fodder of chickens in quantities of 2 and 6% and during a 90-day introduction into concentrations 1, 3 and 5% the activated bentonite and not provoke any changes in the behaviour, overall state and in the clinical biochemical and electrolytic composition (Ca, P, K, Na) of the blood, but it caused suppression of growth ranging from 6 to 27% and brought about a higher expenditure of food for a single growth unit ranging from 4.7 to 12.1%. This was also observed when it was added to the morning ration of pigs in doses 1 and 5% (6 and 30 d/pig) without any influence over the health state of the pigs, but it slowed down growth ranging from 17.2 to 21.3% and a lower utilization of the fodder taken by 19 to 26%.