The Rheology of Gel Formed During California Mastitis Test

Mastitis influences milk quality and early detection ofmastitis is important. Three major mastitis detection methods areFoss Analysis, Whiteside Test and California Mastitis Test (CMT).CMT is more likely to be applied for monitoring mastitis on-line,yet some uncertainty exists regarding the rheology of CMT gel andfactors that influence the CMT accuracy. In this book, studies werefocused on the rheology of CMT gel to understand the mechanism ofgel formation and how various factors influence the rheology of thegel. It was found that CMT gel is a DNA/histone/surfactant complex,which is a time- and shear-dependent, non-Newtonian fluid. Sincethe reliability of the CMT hinges on the correlation betweenviscosity and somatic cell count (SCC), this study investigatedspecific factors that may influence gelation. These were rheology,testing conditions (such as time delay), shear rate, temperature,surfactant type and concentration, and milk composition. It wasfound that when using capillary or Brookfield viscometry a linearrelationship exists between the viscosity of the gel and the SCC;however, Brookfield viscometry was found to be more sensitive atthe lower SCC range.