Study On The Effect Of Water-soluble Chitosan On Mastitis In Dairy Cow

Different experiments were conducted in the present study to investigate the effect of water-soluble chitosan on the bacteriostasis bacteria detached from clinical mastitis in dairy cow, on immune function , on safety used on dairy cow, on yield performance and on treatment effect on clinical and subclinical mastitis. The principium results showed that the antibacterial ability of water-soluble chitosan was perfect whether inside or outside. In the same time the water-soluble chitosan is not only safety used on dairy cow but also can increase the immune function and yield performance.The water-soluble chitosan' s minimal inhibitory concentration(MIC) were conformed on the main bacteria which caused mastitis in dairy cow by using doubling dilution. The chitosan agar culture medium and diffusion disc were made according to MIC. The results showed that Escherichia coli. Staphylococcus aureus, Salmonella and Streptococcus could be inhibited by water-soluble chitosan with certain concentration. Otherwise the more the concentration is, the more significant the effect' is.The solution containing 200mg/L iodine-chitosan within 10 minutes contact time could kill 100% of Escherichia coli , Staphylococcus aureus, Salmonella and Streptococcus,The result show Iodine-chitosan solution neat disinfectant for cows had activities to kill the tested bacteria.Systematic toxicological studies were performed on water-soluble chitosan used on dairy cow. The result show it issafety on dairy cow whatever we inject the water-soluble chitosan into udder or profess to convinced or bath the cow nipples.Dairy cows of the trial group was fed with 0. 5 percent of water-sobuble chitosan for 35 days and mensurate some index of immune function and yield performance. The result show that water-soluble chitosan can increase the number and percentage of lymphocyte^ the lymphocyte transformation rate of T lymphocyte and the content of IgG ; at the same time chitosan can increase not only the milk production and the content of fat , but also the content of protein and total dry material . So we kan conclude that water-soluble chitosan can enhance the immune function and the yield performance of dairy cows.The treatment experiment was perfored in dairy cows with clinical and subclinical mastitis. The result show in clinical mastitis chitosan plus cefotaxime had the highest clinical cure rate, cefoxime took the second place and chitosan took the third place. The dairy cows which have subclinical mastitis were fed chitosan at 20g/d per cows for 6 weeks, in the cure group chitosan cut down the somatic cell counts (SCC) of milk significantly and the herifer positive rate, in the same time chitosan increase the milk yield and improve the milk quality. So we drew a conclusion than water-soluble chitosan have good effect on clinical and subclinical mastitis in dairy cows.