The aim of this study was to investigate the effects of nano zinc oxid (nZnO) on blood zinc level and two related enzymes activity in Markhoz goat kids. Eighteen male Markhoz goat kids aged 6-7 months in a completely randomized design were allocated into 3 treatments including zero (control), 20 and 40 ppm zinc from nZnO source and fed with a basal diet (containing 22.12 mg Zn/kg DM) for 70 days. The nZnO as a zinc supplementation were added to the basal diets and were offered daily at 08:00 and 17:00 h in two equal portions. Blood samples were taken on days 1, 35 and 70 of the experiment before morning feeding via the jugular vein. The samples were analyzed for plasma zinc concentration (in an air-acetylene flame on an atomic absorption spectrophotometer), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) enzymes activity of the serum (using commercially available kits with an Auto Chemistry Analyzer). The results showed that nZnO did not affect plasma Zn concentration and serum ALP of the kids in our experiment. For treatment 2 in day 70 the activity of LDH was found significantly higher than other treatments. The results showed that the levels of 20 and 40 mg Zn/kg DM from nZnO source had no effect on plasma zinc level and serum ALP and LDH activity in Markhoz goat kids fed a diet containing 22.12 ppm zinc
