3M.M Schutz.Genetic evaluation of somatic cell scores for united states dairy cattle. [J] J.Dairy Sci,1994(77)7:2113-2129.
4H.D .Norman,et.al.Herd and state means for aomatic cell count from dairy herd improvement.[J]J.Dairy Sci,2000 (83)11:2782-2788.
5M.Chassagne.et.al,Expert assessment study of milking and hygiene practices characterizing very low somatic cell score herds in France.[J]J.Dairy Sci.2005(88)5:1909-1916.