[Effect of different amounts of carbamide on the state of health of broilers. I]

Three experiments were carried out with a total of 100 broilers each, divided into five groups of 20 birds. The effect was tested of urea on their health status, it being added to a ration that was balanced in terms of protein in progressively rising amounts of 0.3 to 6.0 per cent within the period of from the 20th to the 60th day. It was found that in amounts of 0.3 to 3.0 per cent urea does not lead to any clinical and morphological changes in the organism of the treated birds. At rates of 4.5 and 6.0 per cent, however, there appear disturbances in the alimentary tract, lack of appetite, thirst, diuresis, hyperemia and hypertrophy of the kidneys. The addition of urea in such amounts to the ration raises the content of urea in the organism from 2 to 5 times, and the amount of retained nitrogen (NPN)--as much as twice in the blood.