Abstract: This experiment was conducted to study the effects of different kinds and levels of acidifier on the fresh-keeping of feeds and diarrhea of growing mink. 100 male minks were randomly divided into 10 groups and 10 minks in each group.Ⅰgroup was fed basal diet.Ⅱ to Ⅹ groups were supplementation with different kinds and levels of acidifier in basal diet, that were 0.4% （Ⅱ）, 0.6% （Ⅲ）and 0.8% （Ⅳ） phosphoric acid, 0.5% （Ⅴ）, 1.0% （Ⅵ）and 1.5% （Ⅶ） citric acid, 0.5%（Ⅷ）, 1.0% （Ⅸ） and 1.5% （Ⅹ） lactic acid, respectively.The trial lasted for 62 days.The results indicated that acidifier could reduce the acid value （AV）, carbonyl value （COV） and total volatile basic nitrogen （TVBN） levels of fresh feeds, restrain the oxidation metamorphic process of fat and protein and improve the preservation ability of fresh feeds, and the 1.5% lactic acid was the best one.The number of Escherichia coli （37 ℃） were significantly affected by dietary acidifier, when tested the number of Escherichia coli at 1 hour, 1.5% citric group was the lowest one （P＜0.01）, at 4 h, the number of Escherichia coli was the lowest in 0.4% phosphoric acid group （P＜0.05）, at 8 h, the lowest Escherichia coli number was found in 1.5% lactic acid group （P＜0.05）.Supplementation with acidifier could extremely significantly reduce the acidifier index and diarrhea rate of growing minks （P＜0.01）, so it had a great significance to relieve the diarrhea of minks in summer.In conclusion, the best level of lactic acid was 1.5% in diet for minks.

Key words: acidifier; mink; fresh-keeping of feeds; diarrhea