Abstract: Plasma copper concentration and ceruloplasmin(CP) activity of 11 lactating dairy cows from a farm were detected in Daqing, and a correlation of both parameters was analyzed, before and after addition of copper preparation to diet. Results shown that before addition of copper preparation, ratio of dairy cows with plasma Cu level below 11.1 μmol/L were 54.54%, and activity of plasma CP was lower than normal level, but correlation of both is better positive(R2=0.53). After addition of copper preparation, both were increased(P<0.01), plasma copper concentration were in normal range, but correlation of both is lower positive(R2=0.12). Conclusion obtained that hypocupremia existed in this dairy farm, the activity of plasma CP may be a detecting index of hypocupremia.

Key words: dairy cattle; plasma copper; ceruloplasmin