Correlation Between The Number Of Somatic Cells In Goat Milk And Milk Components And The Function Of BIRC3

Mastitis is a common disease in dairy goat breeding.It is an inflammatory reaction caused by the infection of pathogenic microorganisms in breast tissue or external physical and chemical stimulation.It can cause many problems such as the reduction of lactation and the decline of goat milk quality,which has a serious impact on the dairy goat industry.Pathogenic microorganism infection is the main cause of mastitis,among which Staphylococcus aureus is one of the main pathogenic microorganisms causing mastitis.Therefore,exploring the pathogenesis of Staphylococcus aureus mastitis is of great significance to improve dairy quality and find new effective methods to prevent and treat mastitis in dairy goats.Through the detection and statistical analysis of the somatic cell number,milk composition and milk yield of 1283 dairy goats from five dairy goat farms in Guanzhong,Shaanxi Province,this study explored the distribution of somatic cell number in sheep’s milk and the correlation between somatic cell number in sheep’s milk and milk composition and milk yield,so as to provide reference for the healthy development of dairy goat industry;Our research group found that birc3 may be involved in the regulation of mastitis induced by Staphylococcus aureus in dairy goats through weighted gene co expression network analysis(WGCNA);Birc3 encodes iap-2 of inhibitor of apoptosis protein(IAP).Some studies have found that birc3 not only plays a role in the process of apoptosis,but also plays a regulatory role in a variety of inflammatory processes.In this study,goat mammary gland epithelial cells(gmecs)were used as the research object.The Staphylococcus aureus isolated from milk samples of dairy goats with clinical mastitis was inactivated by formaldehyde and collected to obtain formalin killed Staphylococcus aureus(FKS.A);Use FKS A stimulate gmecs,construct goat mammary epithelial cell inflammation model,and explore the regulatory effect of birc3 on gmecs apoptosis and inflammatory cytokine secretion in golden grapevine mastitis.The main results are as follows:1.The proportion of somatic cells < 500000 / m L in goat milk was 34%,the proportion of somatic cells in the three groups of 500000-1 million / m L,1-2 million / m L and 2-5million / m L was close,16%,17% and 20% respectively,and the proportion of somatic cells> 5 million / m L was 13%.2.There was a significant positive correlation between the number of somatic cells and milk protein rate in goat milk(r = 0.231,P < 0.05);And lactose content(r =-0.421,P <0.01);There was a significant negative correlation with the content of total solids(r =-0.356,P < 0.05),and a very significant negative correlation with the content of urea nitrogen(r =-0.302,P < 0.01);There was a significant negative correlation between and milk yield(r =-0.396,P < 0.05).The increase of somatic cells in goat milk resulted in the decrease of lactose,total solid content,urea nitrogen content and milk yield;3.Use 106 CFU / ml,107 CFU / ml,108 CFU / ml FKS A treat gmecs for 0h,12 h and24h to explore FKS A the optimal concentration and time of constructing Staphylococcus aureus inflammatory cell model,the results showed that 108 CFU / ml FKS A treatment of gmecs for 24 hours,cytokine IL-1 β、 The expressions of IL-6 and TNF-a were significantly up-regulated(P < 0.05);4.In vitro cell test study found that FKS A treatment of gmecs for 24 hours could up regulate the expression of birc3(P < 0.05).Birc3 inhibited apoptosis by inhibiting the activation of Caspase-3;Promote gmecss IL-1 by mediating the activation of Caspase-1 βSecretion of;5、FKS.The expression of phosphorylation and phosphorylation of pyr-2 and pyr-6-5was induced by using the inhibitor of phosphorylation of pyr-6-5 and pyr-6-5 A.when gmecs were treated together,the expression of birc3 in inhibitor group was inhibited compared with DMSO treatment group;To sum up,in actual production,mastitis of dairy goats will lead to the decline of milk production;The total solids and lactose in goat milk decreased,which affected the quality of goat milk;In the inflammatory cell model,Staphylococcus aureus promotes the expression of birc3 through tlrs-myd88-p65 signal axis,and birc3 inhibits apoptosis and the secretion of inflammatory factors by inhibiting the activation of Caspase-3 and mediating the activation of Caspase-1.These functions make it a potential target for the prevention and treatment of dairy goat mastitis in practical production.