Abstract: Studies on effects of selenium,copper,zinc in serum of different kinds of sheep in pregnancy which were added selenium in the identical condition of feeding management.There were 85 sheep in pregnancy including Mongolian sheep,Dorset and Suffolk sheep, determined contents of selenium by fluorescence spectrophotometry method, determined contents of copper and zinc by atomic absorption spectrophotometry method.Results showed that from pregnant 3 months on, the content of selenium in serum of each kind sheep which was added selenium was significantly higher than that of the same kind sheep which was non-added selenium, and at the same time, the content of zinc in serum was non-significantly (P＞0.05) between the same kind of sheep which were added selenium and non-added selenium,and the content of copper in serum was non-significantly (P＞0.05) between added selenium and non-added selenium Mongolian sheep.Results indicated that there is no antagonism between selenium and copper or selenium and zinc,so added selenium could play an important role to maintain natural pregnancy and to enhance resistibility.

Key words: sheep; pregnancy; selenium; copper; zinc