Abstract: [Objective]This experiment was conducted to study the effect of lysozyme on calf diarrhea and growth performance when used in different amounts.[Method]A total of 100 healthy calves with similar body size and no disease were randomly divided into 4 groups with 25 calves in each group,which were control group and low-dose group （group Ⅰ,1 g/h·d）,medium-dose group （group Ⅱ,3 g/h·d）,high-dose group （group Ⅲ,5 g/h·d）,the experiment lasted for 30 days,and the feces and diarrhea of calves were recorded and observed at the beginning and end of the experiment,as well as the changes in body weight and body size of calves.[Result]The use of lysozyme had an effect on the fecal score of calves during the whole experimental period.The fecal score of group Ⅲ was significantly lower than that of the control group at days 1~30（P<0.05）,and that of group Ⅲ was 12.5% lower than that of the control group.The diarrhea rate of groupsⅠ,Ⅱ and Ⅲ was significantly decreased by 23.02%,41.81% and 53.64% compared with the control group at 1 to 15 days（P<0.05）,indicating that the use of lysozyme was large,and the diarrhea effect was more obvious. The average daily weight gain of calves in both group II and group III with the addition of lysozyme was significantly higher than that of the control group (P < 0.05),by 9.6% and 12.0% respectively;the chest circumference of group III was significantly higher than that of the control group,3.0% higher.[Conclusion]The use of lysozyme in appropriate doses can not only reduce the diarrhea rate of calves,but also promote the growth performance of calves.

Key words: lysozyme, growth performance, fecal score, diarrhea rate