How do you find out what caused a milk grade?

Grades cost you money, milk, and reputation. But before you start replacing rubberware or blaming the vat, stop and think: grades aren't random. They're caused by something specific, and that "something" can usually be found and fixed fast... if you know where to look. Have a read here and check in with Max the Grade Guru.

What should you check first when a grade lands?

When a grade lands, don't panic. Start smart and work systematically.

1. What kind of grade is it? 

- Coliform?

- Thermoduric?

- Bactoscan?

2. What changed recently? 

- New staff?

- New wash routine? 

- Different chemical supplier and/or new cleaning routine? ***It can affect.

- Skip-a-day collection?

3. When was your last good result?

- Compare milkings.

- Match changes in cleaning or milking practices.

4. What's your gut telling you?

 - Trust experience and then back it up with evidence.

What's worth checking, and what's a waste of time?

There's a difference between solving a problem and just doing stuff. Too many people throw time and money at the wrong target. Here’s how to avoid that:

Is your grade a hygiene problem or something else?

Not every bug in the vat came from a dirty plant.

It's probably hygiene if:

• There's a visible build-up (especially protein)

• Hot water is borderline or inconsistent

• You haven't done a full inspection in weeks

• Grades follow a pattern (e.g. same milking each time)

It's probably not hygiene if:

• The grade appeared suddenly with no changes

• The milkline and vat look spotless

• There's a spike in somatic cell count at the same time (pointing to mastitis)

• The lab identifies environmental bacteria or spores (often linked to silage)

Where should you start a plant inspection?

Most people begin inspections at the cow shed. Wrong.
Start at the vat and work backwards, it’s generally a quicker inspection as 1 in 4 hygiene grades can be traced to the vat. Starting here saves you spending hours looking elsewhere first. 

What are the first ten things to check after a grade?

1. Vat interior (look for protein film)

2. Stirrer and valve seals

3. Filter tube (especially top lip)

4. Liner ends (feel and sniff!)

5. Milkline joints and high points

6. Claw bases and sight glasses

7. Jetters (check for blocked or faulty ones)

8. Receiver (especially upper surfaces)

9. Wash water temperature log (start/dump temps)

10. Last 7 days' cleaning routine (alkali/acid schedule)