[Effect of various protein levels in the diet on the activity of some metalloenzymes].

Studies on the effect of increasing protein levels in the diet (0 to 50% casein) on hematological criteria (v. Krziwanek et al., 1978) were supplemented by experiments regarding the reaction of catalase, ceruloplasmin and alkaline phosphatase under such conditions. A relationship was found between the activity of all 3 enzymes and protein supply. The catalase activity of the blood revealed a linear relationship with the protein level of the diet. The activity of the alkaline phosphatase was found to go up as the protein level of the diet increased reaching its maximum with weight development. The ceruloplasmin activity revealed an opposite behaviour. The results show that the application of these criteria for measuring the supply with and conversion of trace elements do not allow reliable statements but under constant experimental conditions. The catalase activity in the blood may give certain clues for assessing the quality and quantity of protein in the feed.