The aim of this study was to determine the risk factors associated with
high total bacterial count of bulk tank milk. Bulk tank milk samples
were collected from all Prince Edward Island dairy herds (n=235)
from March 2005 to March 2007. Biweekly total bacterial count was
conducted using a Petrifilm culture system. Data for on-farm risk
factors were collected via a mail-out survey which consisted of 4 main
sections: 1) general farm demographics and management, 2) cow
cleanliness and hygiene, 3) milking procedures and mastitis control,
and 4) equipment maintenance and cleaning.
The total bacterial count was positively associated with the amount of
soiling on the teats prior to udder preparation, manual cleaning of the
bulk tank, and the use of a certain type of detergent. Additionally, various
methods of premilking udder preparation were important, with predip < br />followed by drying being superior to other methods in reducing
bacterial count. Season was a strong predictor, with the lowest count
tending to occur in winter. The results of this study highlight the
importance of total bacterial count as indicator of on-farm management
practices, which influence bacteriological quality of milk.