Changes of Cytokines in Serum and Whey of Dairy Cows with Subclinical Mastitis

In order to study the correlation of different degrees of subclinical mastitis and cytokines,the changes of interleukin-1β （IL-1β）,interleukin-6 （IL-6）,interleukin-8 （IL-8） and tumor necrosis factor-α （TNF-α） in blood and milk and whether the changes of these indexes were caused by mastitis were analyzed.The 40 Holstein cows in lactation period were tested and grouped by somatic cell count （SCC） method in milk:Group C (SCC＜5×10~5 cells·mL^-1),Group I (5×10~5 cells·mL^-1＜SCC＜1.5×10~6 cells·mL^-1),Group II (1.5×10~6 cells·mL^-1＜SCC＜5×10~6 cells·mL^-1) and Group III (SCC＞5×10~6 cells·mL^-1).The contents of IL-1β,IL-6,IL-8 and TNF-α were analyzed by radioimmunoassay.The results showed that the contents of IL-6,IL-8 and TNF-α in the blood and milk of different degrees of subclinical mastitis increased with the severity of mastitis,and were higher than those in normal group.The contents of IL-6,IL-8 and TNF-α in serum and whey of dairy cows affected by different degrees of subclinical mastitis were higher than those in normal group （Group C）.The content of IL-1β increased and decreased with the increase of inflammation,and it did not have the value of evaluating mastitis.In conclusion,the severities of cow subclinical mastitis and the contents of cytokines were positive correlations.These indexes could be used as the basis for judging mammary gland injury.