Emily Darchuk and Dr. Lisbeth Goddik with partnership from the

Emily Darchuk and Dr. Lisbeth Goddik
with partnership from the Washington Dairy
Products Commission



PMO requires that dairy tankers are CIP’d
following 24 hrs of use
Trucks can pick up multiple loads or cover
vast distances with or without milk
Tracking quality changes between the farm
and plant is difficult
1.
2.
Determine the impact of operating trucks
for an extended period of time (24 hrs)
Impact of reusing a truck up to 10 times in
between CIP treatments
3.
Impact of different cleaning procedures
4.
Impact of seasonality
1.
2.
3.
4.
Standard use ( 24 hr CIP)
Water rinse after each load
Water rinse after each load & sanitizer treatment after 12 hrs
Sanitizer treatment after 12 hrs
Provides
baseline
milk quality
data
Shows the
effect of
hauling
Shows impact of
frequent use
without cleaning
Impact of
frequent use
and the
efficacy of
cleaning

Study was designed to minimize impact to
production facility
•All data was tracked using
information captured on the Bill of
Lading (BOL)
•A duplicate set of samples were
taken for this study
•All samples were shipped to
corporate lab for analysis
•24 hr plant support was provided
by an OSU student for the start of
the study
◦ Hauler sampled at
each farm prior to
loading
◦ Served as the
control sample for
starting milk quality
◦ Individual samples
used for tanker
weighted average

PRODUCER SAMPLE
◦ Receiver took a
sample prior to unloading
◦ Samples taken from
front and back
trailer
◦ Compared to
producer to
determine the
impact of hauling

TANKER SAMPLE

TANKER SWAB SAMPLE
12 am/ 12 pm Swab Area
9 am/ 9 pm Swab Area
3 am/ 3 pm Swab Area
6 am/ 6 pm Swab Area


Hoses used to receive all
loads in facility
Samples were taken after
every 6 hrs of use

ENVIRONMENTAL SWAB :
Receiving Hose
◦ Total Bacteria Count
◦ Thermophilic Spore Count
◦ Preliminary Incubation (PI)
Over 4000 data points were analyzed for
this study
◦ 139 Tanker Loads
◦ ~ 600 Milk Samples
◦ ~500 Swabs
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
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There was no impact from the different trucks
used or the front vs. back trailer
Milk quality is highly variable and requires a
methodical design to capture results
These studies are very labor and time
intensive but critical to understanding the
entire milk processing chain

There is no evidence that additional cleaning
treatments improve milk quality
◦ Currently the PMO is adequate

Environmental sampling shows potential for
growth over time



Continue data analysis
Repeat study in the
summer months
Investigate the impact
of long haul shipping

Dr. Lisbeth Goddik – Professor and Advisor
◦ Lisbeth.Goddik@oregonstate.edu

Gina Shellhammer -Statistician
◦ Gina.Shellhammer@gmail.com

Washington Dairy Products Commission

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