[Incidence of inhibitory substance-residues in meat and organs of slaughter calves fed with milk feed mixtures].

From 1st January 1974 till 30th April 1975 the frequency of the occurrence of growth inhibiting substances in meat and organs of slaughter calves on milk feeding was studied. Meat and organs of 11 226 calves on milk feeding (the meat and organs were judged, after the veterinary inspection, as fit for concumption), of 189 emergency-slaughtered calves on milk feeding and of 751 forced--slaughtered calves were examined by means of a diffusion plate method with the tester stran B. subtilis (ATCC 6633); the method had been, on trial, introduced into State Veterinary Institutes. The positive findings in all groups studied considerably fluctuated and showed average values as follows: 6.3% --14.28% --22.5%. At the same time, 71 clinically healthy calves were examined; they were slaughtered in the slaughter -- houses of M. meat processing plant after having been reared in a traditional way. In this group, all results concerning the examination of the presence of growth inhibiting substances were negative.