Mastitis Risk Assessment and the PA Dairy Tool
The PA Dairy Tool and Milk Quality and Udder Health Assessment or Drill
Down Tools were recently developed by a team of dairy educators within
Penn State Dairy Extension. Dr. Dave Baver (Western Pennsylvania) and
Rob Goodling (Berks/Lebanon counties) were instrumental in developing
the milk quality and udder health risk assessment and software analysis
tools. As described in a previous article in the Dairy Focus, the
overall PA Dairy Tool allows your consultant to evaluate the production
factor(s) that have the greatest impact on profitability. This article
will focus on the Milk Quality and Udder Health Tools developed for
further investigation of mastitis risk. The tools can be used after
milk quality is identified as a key factor impacting herd
profitability. These tools can also be used alone to troubleshoot herd
milk quality and udder health concerns or to identify factors key to
increasing milk quality premiums.
The Milk Quality and
Udder Health Risk Assessment Tool is a checklist that separates risk
into five primary categories and provides visual feedback to
communicate the primary contributors to high bulk tank somatic cell
count, clinical mastitis rate, or high cost of mastitis. The risk
categories in the tool include: 1) Milking Management Risk for New
Infections, 2) Environmental Risk for New Infections, 3) Animal Health
and Biosecurity Risk, 4) Culling and Treatment Risk, and 5) Sanitation
Risk. Within each category are those factors that are considered to
have the highest contribution toward milk quality and mastitis risk.
Each factor is scored as having a low limitation (green) and having no
major impact on mastitis risk, a moderate limitation (yellow), or a
high limitation (red) toward mastitis risk. The consultant and producer
can then quickly look down the checklist to identify which factors
(yellow and red) on the dairy are contributing most to mastitis risk. A
plan can then be developed to work toward lowering risk for new
mastitis and reducing milk quality and udder health impact on overall
herd profitability.
The Somatic Cell Count Analyzer Tool
The software analyzer can be used to identify and provide details about
cows having the greatest contribution to herd bulk tank somatic cell
count. The analyzer can also be used to monitor herd progress toward
lowering bulk tank somatic cell count.
Overall mastitis
level in the herd is due to a combination of cows with long-term
mastitis infections, or chronic cows, and new cases of mastitis (new
infections). We use current and historical somatic cell counts to
identify those cows with short-term or long-term subclinical mastitis
infections. The Somatic Cell Count Analyzer takes your DHI somatic cell
count (SCC) records and quickly ‘processes’ this information and
highlights problem cows and problem cell counts over the last 10 months
for individual cows. This easy to follow layout will make it easier to
discuss chronic cows or new mastitis cases with your veterinarian,
determine best treatment plan for cows with clinical mastitis, and to
follow impact of clinical treatment on subclinical mastitis in
individual cows.
Figure
1 provides an example from the Somatic Cell Count Analyzer and a visual
display of a few chronic cows in a herd with high bulk tank somatic
cell count. Cow 80 (see above the arrow) was 198 days in milk at her
current herd test. She had a somatic cell count (SCC) of 7.3 million at
this test. The test day before that she had a 9.7 million SCC. In her
first month of lactation she had a SCC of 857,000. She is classified as
a chronic cow, meaning she will likely always be infected, and she had
7 high counts in her current lactation. If not previously cultured or
treated, a milk sample should be taken from the infected quarter(s) to
identify the bacteria causing the infection and the drug most likely to
cure that infection. If she was treated with that antibiotic and it was
not successful, it may be best to cull her and replace her with a
noninfected cow.
The analyzer provides similar lists for
cows with new subclinical infections started during the dry period
(cows with low SCC at last test day before dry-off and high SCC at
first test after calving), chronic dry period infections (high SCC at
last test before dry-off and first test after calving), recovered
subclinical infections (cows with high test on previous test day and
low cell counts on most current test day and not chronic), and new
heifer infections (high SCC at first test day). Use of this information
with on-farm clinical mastitis records can provide you with valuable
easy to follow records for improved treatment and culling decisions. It
can also help you to decide if a particular treatment protocol appears
to be working or not working in your herd.
If interested in
receiving a Milk Quality Risk Assessment in your herd or your client’s
herd, or, you are interested in learning how to use the Milk Quality
Tools with your clients, call your Penn State Extension dairy educator.
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Sandy Costello, Extension Educator - Dairy Herd Health, Penn State Cooperative Extension, Cumberland County
