Analysis of milk quality in a mid-sized Holstein herd

Abstract

A mid-sized Holstein herd experienced a rise in bulk milk somatic cell count (BTSCC) and clinical mastitis in the previous year, and the previous month's BTSCC was >400,000 cells/mL. Poor milk quality creates financial losses on the farm, including loss of premiums and milk yield. As part of the Quality Milk Production Services course, our group evaluated the farm for problems and potential solutions. Using DHI test day records, we found an elevated incidence of fresh infections (20%) - particularly in the first-lactation animals (>50%). Cases of clinical mastitis on the farm clustered at the early fresh period, but many cases also appeared later in lactation, indicating two potential sources of infection. Pathogens identified from milk sampling included Streptococcus uberis, Staphylococcus spp., E. coli, and Prototheca. Infections were attributed to over-crowding in the dry period, co-mingling recently fresh cows with sick and treated cows, and contamination in the milking parlor.