Dairy Cattle in Mississippi
Bulk Tank Somatic Cell Count
Somatic cells are actually white blood cells (leukocytes) that are secreted in increasing amounts into the udder (milk) when an inflammation such as an infection (mastitis) occurs. Bulk tank somatic cell counts are effected by the number of infected cows being milked into the tank. It is normal to experience increases in bulk tank somatic cell count levels during periods of low milk production such as hot weather (heat stress) or marginal nutrition. However, when bulk tank somatic cell counts exceed 4, determining which cows have mastitis is best accomplished by analyzing each individual cow's milk for somatic cells. Utilizing management tools such as DHIA (Dairy Herd Improvement Association), or the California mastitis test, to determine those animals that are contributing the most to the bulk tank somatic cell count can do this. Removing these cow's milk from the bulk tank will lower the bulk tank somatic cell count level, but only temporarily solves the problem.
A more efficient approach for managing bulk tank somatic cell counts is to determine the source or cause of the mastitis and reduce the number of cows becoming infected. This will provide savings by reducing discarded milk, treatment cost and labor. In addition, cows with low somatic cell counts produce more milk which makes them even more efficient.
For additional information please refer to articles found in the Mississippi Dairy Newsletter from August 1997, November 1996 and January 1996. In addition, there is an excellent paper written by Dr. Gary Hay, Extension Dairy Specialist from Louisiana State University which, can be found in the proceedings of the 1997 Mississippi/Louisiana Dairy Management Conference.
