Here you’ll find an explanation of what FEI is and why it matters, how to check and manage your score, and what research shows about the impact of different feeds, including PKE.
Summary:
FEI helps ensure milk fat is suitable for making high‑quality dairy products. It reflects how feed choices - such as PKE use - diet balance, and stage of lactation affect milk fat composition.
Check your FEI results
In the On-Farm App
1. Open the On-Farm app
2. Go to Daily Results
3. Tap the arrow above Downgrades to move to next screen
4. Select FEI Average on the graph view
The graph gives the best picture of your farm’s FEI because it shows your 6‑day rolling average.
Other places
Manage your FEI
Find out how FEI testing works, tips for managing your score, and research on PKE and fodder beet.
Frequently Asked Questions
We need milk with the right fat composition so the Co-op can make products that meet customer needs and get the best value from every drop.
Feeds like PKE can change milk fat, so we introduced the Fat Evaluation Index (FEI) system in 2017.
FEI helps farmers supply suitable milk while still using PKE as an affordable feed option. We review the system regularly and update it when needed.
The key driver when it comes to high FEI milk is an increased use of PKE as stock feed.
The level of oil content of PKE is also important. This can vary by region or origin, time of year, supplier and by shipment.
The composition of milk fat is also impacted by other factors, including:
- Environment (including time of year, region, climate and grass quality)
- Breed of the cow (Jersey vs Kiwicross vs Friesian)
- Genetics and weight of the cow
- Stage of lactation of the cow
- Cow feed (including grass and supplementary feeding)
It's also important to note that even milk from grass-fed cows will register an FEI.
High FEI milk can make processing less efficient. Butter is most affected – texture and quality can suffer. It can also impact creams, Anhydrous Milk Fat (AMF), and products made from these.
Track how much PKE you feed and its share of the diet. Weigh feed when loading – volume can be misleading because density changes.
Feeds like fodder beet and turnips can also raise FEI by changing rumen balance, especially when fed with PKE.
Replacing PKE with other feeds usually lowers FEI, as long as cows still get the right nutrition. Always work with a consultant or nutritionist when changing feeds.
FEI results are shown on a scale from 1 to 16. Grading thresholds decide if milk gets a minor downgrade, major downgrade, or reject rating.
Two tests are used:
- A daily screen gives a 6-day average result.
- If three results are above the threshold, a confirmatory test is done.
Downgrades mean deductions from the Milk Price (5% minor, 20% major). A reject rating means no payment for that day’s milk.
We review our FEI framework on regular basis.
View the thresholds and downgrade system that applies for current season.
The Co-op pays for daily screening. If a confirmatory test is needed and confirms a downgrade, the farm pays for that test.
Results are on your milk docket, on the Farm Source website, and in the On-Farm app under Daily Results. Use the graph view for the best picture – it shows a 6-day rolling average.
Call the Farmer Support Team on 0800 65 65 68 or contact your local Co-operative Services Area Manager. For feed advice, talk to your consultant or Dairy NZ.
Call the Farmer Support Team on 0800 65 65 68 first. If you are still not satisfied, then you have the option to lodge a dispute under the Fonterra Farmers’ Terms of Supply (section 4.6).
PKE is high in protein and energy and is mainly used when grass growth is low, like during drought. Across Fonterra farms, cows are about 96% grass-fed.
Small amounts of PKE help keep cows healthy without affecting milk safety or quality.
Feeding high levels to lactating cows can affect FEI, so it needs to be managed.
To read more about this, click here.