Resources / Dairy / Days in milk
Dairy · Milk yield · Herd

Days in milk

175 days average

How long cows have been lactating, viewed as the spread of the herd across stages of lactation. In a year-round herd a steady, even spread is what keeps the vat full month to month.

Worked example · Cows by days in milk
68 74 72 66 0–60 60–120 120–200 200–305
Cows by days in milk
The benchmark

Aim to hold average days in milk near 160–180 in a year-round herd; a rising figure signals cows not getting back in calf.

Dairy Australia · InCalf ↗
What it signals

Average days in milk drives total vat volume and feed demand. A herd bunched in early lactation is near peak and hungry; a climbing average signals cows failing to get back in calf and dragging production down.

Data required to calculate
Calving date per cowdateCurrent datedate

Silo pulls each of these from the sources the operation already uses, and keeps the figure current automatically.

How to improve it
01

Hold the 100-day in-calf rate so cows re-calve on schedule.

02

Dry off chronically late, low-yielding cows rather than carrying them.

03

Use the distribution to plan feed and grouping through the year.

Questions & answers

What is days in milk?

How long cows have been lactating, viewed as the spread of the herd across stages of lactation. In a year-round herd a steady, even spread is what keeps the vat full month to month.

What data do you need to calculate days in milk?

You need: Calving date per cow (date), Current date (date). Silo pulls each of these from the sources the operation already uses and keeps the figure current automatically.

What is a good days in milk benchmark?

Aim to hold average days in milk near 160–180 in a year-round herd; a rising figure signals cows not getting back in calf.

How do you improve days in milk?

Hold the 100-day in-calf rate so cows re-calve on schedule. Dry off chronically late, low-yielding cows rather than carrying them. Use the distribution to plan feed and grouping through the year.

More dairy guides

All dairy KPIs →

See this KPI live for your own operation.

Connect the software, spreadsheets and records you already keep, and Silo keeps every benchmark on this page current automatically.

Book a demo