Abstract: 8 clinical health dairy cows (control group)and 16 foot-rotten dairy cows were selected and were collected serum, milk, urine, feces, wool and hoof horn before feeding in the morning, the feedstuff were collected, too. The all collection were dried and then measured the zinc level by atomic absorption spectrophotometer.The result showed that the zinc levels in serum and hoof horn of the foot-rotten group significantly decreased（P＜0.01）, in comparison with the results in control group, but no significant difference was observed in milk, urine, excrement and wool （P＞0.05）. The analysis of zinc levels in diet indicated that the zinc deficiency in foot-rotten cows seemed no relevance with the diet. The zinc deficiency, especially zinc deficiency in hoof horn, implied the closely relationship between the occurrence of foot rot and zinc deficiency.

Key words: dairy cow; foot rot; zinc nutritional status