MlLKBVG-TO-MlLKING VARIABILITY OF SOMATIC CELL COUNTS IN A 3X-MILKED DAIRY HERD AND EFFECT ON RANKING ON DHIA HOTLIST

摘要

Dairy producers in Florida face a financial penalty if the milk they ship has a somatic cell count (SCC) greater than 750,000. When the bulk tank SCC is high, which may be the case during hot, humid summers, a suggested quick remedy is to withhold themilk of the cows that are expected to contribute the most somatic cells to the bulk tank. The SCC of a cow is normally determined by DHIA during only one or two milkings in a month on the testday. Each testday, DHIA calculates a "Hotlist" of the 20 cowsthat contributed the most somatic cells to the bulk tank. Because of the inherent variability in SCC from milking to milking, the value of the "Hotlist" as a guide as to which cows to withhold milk from is not clear. Data on milking to milking variationin SCC is scarce. Objectives of this study were 1) to measure the milking to milking variability of SCC in a herd with a high bulk tank SCC and 2) compare the ranking of cows based on their contribution of somatic cells to the bulk tank from milking tomilking.