Zinc is the only metal that is found in all enzyme classes. And as a cofactor for more than 300 metalloproteinase enzyme involved in the metabolism of proteins, lipids, carbohydrates, protein synthesis, DNA transcription operates. The aim of this study was to investigate the effect of the organic source of liver enzymes (alanine aminotransferase and Sparatat aminotransferase) Holstein calves using 15 male calves were studied in a completely randomized design with three treatments The treatments were: diet without zinc supplementation (control), one treatment with 250 mg (glycine) and two treated with 500 mg of zinc (glycine). The results showed that the organic supplements, had no significant effect on the concentration of AST (P>0.05). But significantly reduced serum ALT levels (p<0.05).