~1H Nuclear Magnetic Resonance-based Metabonomics On Early-stage Diagnosis Of Dairy Cow Mastitis

The etiology of cow mastitis is complex,it is one of the most common cow diseases in the world,its cost of treatment is very high,and this disease can cause huge economic loss.Dairy cow mastitis is an inflammatory reaction in mammary tissue.The milk somatic cell count(SCC)and the characteristics of metabolites in the biological fluid of mastitis cows with different degrees of inflammation will necessarily change.Due to the limitations of traditional diagnostic methods,it is difficult to fully elucidate the pathogenesis,the correlation among inflammatory state,somatic cell count and metabolites,and thus cannot meet the needs of researchers.Metabolites in biological fluids of the body are in a dynamic equilibrium under normal conditions.However,some physiological and pathological factors may cause abnormal changes in this state,which leads to certain changes in body fluids.Metabolomics techniques have changed the traditional concept of single biomarker analysis,is a clinical diagnostic technique designed to detect and use the overall metabolic pattern,has been used to characterize the metabolic characteristics of test and control groups,as well as subjects of different health conditions.Using the metabonomics technology study of dairy cow mastitis,can help the researchers to find metabolites that differ between healthy cows and those with different levels of mastitis cows,and make analysis,finally identified biomarkers of dairy cow mastitis,which can help people to recognize more cows breast physiological and pathological changes of the process.In this study,~1H NMR-based metabolomics was used to evaluate the metabolism of whey and plasma in mastitis cows.In this study,the experimental animals were divided into 4 groups(healthy control group,subclinical mastitis group,mild clinical mastitis group and severe clinical mastitis group)according to the somatic cell count in the milk.The purpose was to analyze the plasma and whey metabolism of cows with different degrees of mastitis to assess the differential metabolites among groups.The data of milk and plasma samples were analyzed by multivariate analysis methods in which principal component analysis and orthogonal partial least-squares discriminant analysis were implemented for class discrimination and biomarker identification in the present study.The experimental results of this study showed that there were six different metabolites in whey sample groups,which were respectively lactate,alanine,pyruvate,succinate,formate,and sn-glycero-3-phosphocholine were different among the groups.The metabolic level of alanine was reduced while lactate,pyruvate,succinate,formate,and sn-glycero-3-phosphocholine were increased with somatic cell count getting elevated.At the same time,seven different metabolites were found in the plasma samples,which were respectively malonate,phenylalanine,isoleucine,histamine,leucine,glucose,and glycine were different among the groups.The metabolic level of malonate and glycine were increased while phenylalanine,isoleucine,histamine,leucine,and glucose were reduced with somatic cell count getting elevated.Our results showed that ~1H NMR-based metabonomics combined with multivariate data analysis is sensitive and specific to evaluate the metabolite differences between healthy and mastitis cows.It also shows the potential to serve as the early-stage diagnosis method for dairy cow mastitis.