The work describes the effects of cimetidine on stress-induced gizzard ero- sions (Experiment A) and the influence of the long-term application (42 days) of the same drug on weight gain and feed consumption during broiler fattening (Experiment B). For Experiment A, 60 male, three-day-old
chicks were divided into two groups: C (n = 30) Ś control chicks treated with 0.5 ml saline; CIM (n = 30) Ś chicks treated with cimetidine in a dose of 5 mg/kg body weight (b. w.) in - tragastrically. All chicks were stressed using a modified water-immersion stress method according
to which the chicks, after 24 h of feed deprivation, were im - mersed in tap water (17 °C) for a few seconds. Under chloroform anaesthesia ten chicks from each group were killed 1, 2 and 3 h after the stressing. The mor- phometric analysis of gizzard erosion (GE) and histopathological
examinations of gizzards were performed for each chick. In Experiment B, 32 one-day-old broilers of both sexes were used. The control group was untreated (n = 16) while the CIM group (n = 16) was fed the same diet supplemented with 10 mg of cimetidine per kilogram of feed throughout the fattening
period (42 days). The results of Experi- ment A showed decreased mean length of the GE in the cimetidine-treated birds as compared with the GE lesions of the controls. In Experiment B, the treated chicks had reduced liveweight (1835.1 g), carcass weight (1474.6 g) and increased feed consumption
(2115 g of feed per kilogram of weight gain) compared to the con- trols in which the same parameters were 1898.5 g, 1574.2 g and 1797 g, respec- tively. The results show that while stress-induced GE of chicks can be medicated pharmacologically, long-term application of the same substance impairs
the results of fattening.