[Trial of trimedin action on chickens].

Investigations were carried out with a total of 421 broiler birds (four-line Cornish X Plymouth Rock hydbrids) within the age range of 2 days to 5 weeks. Determined was the acute toxicity of the combination sulfadimidine (SDM) + trimetoprim (TMP)--5 + 1 and the water-soluble formula of trimedin following the intraingluvial introduction with week-old birds. LD50 of the combinations SDM+TMP (5+1) was 3980 mg/kg (2780: 5690), and that of trimedin was 2038 mg/kg body mass. The biologic half-life of SDM ranged from 4.77 to 5.34 h, and that of TMP--from 4.81 to 5.71 h at the intraingluvial introduction of the combination SDM+TMP (5+1) at the rate of 0.06 g/kg. Demonstrated were the therapeutic levels of SDM and TMP during the whole period (10 days) of treatment with the combination SDM+TMP (5+1) given with the feed in conc. 500 ppm or at the application of trimedin alone via the drinking water in conc. 0.05%. It was found that trimedin used for 10 days with the drinking water in conc. 0.05 per cent with broilers at the experimental infection with Salmonella gallinarum-pullorum protected about 40 per cent of the birds, the latter remaining, however, carriers of the infection.