What occurs when the mixture of milk and reagent in the CMT becomes gel-like?

When the mixture of milk and reagent in the California Mastitis Test (CMT) becomes gel-like, it indicates a high presence of somatic cells, which are primarily white blood cells. This condition is typically associated with mastitis, an inflammation of the mammary gland, often caused by infection. Somatic cells increase in milk as the body responds to infection, leading to the thickening or gelling of the CMT mixture.

In this context, if the test shows a gel-like consistency, it is a clear indication of mastitis rather than any issues related to fat content or the processes of pasteurization and homogenization. Pasteurization is a heat treatment process that eliminates pathogens and extends shelf life, while homogenization involves mechanically breaking down fat globules to create a uniform milk product. Neither of these processes directly relates to an increase in somatic cells or the gel-like reaction observed in the CMT.