Quick answers
- How much does a cow eat per day?
- A dairy cow eats about 3% of her body weight in dry matter each day. A 450 kg cow needs roughly 13 to 14 kg of dry matter.
- How many bales of hay per cow per month?
- If hay is her main roughage, plan on about 9 kg of hay a day, which is around 18 bales a month at 15 kg per bale.
The quickest way to plan hay is to start from what the animal eats in total, then decide how much of that will come from hay. Everything below uses dry matter, which is the feed left once the water is taken out. Good hay is about 85 to 90% dry matter, so a kilo of hay gives close to a kilo of feed.
Step 1: Total daily intake
A milking cow eats about 3% of her body weight in dry matter each day. High-yielding cows eat a little more; dry cows and heifers a little less. Goats and sheep eat about 3 to 4%.
| Animal | Typical weight | Dry matter a day |
|---|---|---|
| Dairy cow (Friesian) | 450 to 550 kg | 13 to 16 kg |
| Dairy cow (Ayrshire, Jersey) | 350 to 450 kg | 10 to 13 kg |
| Heifer | 200 to 300 kg | 6 to 8 kg |
| Dairy goat | 40 to 60 kg | 1.4 to 2 kg |
Step 2: How much of that is hay?
Very few farms feed hay alone. A milking cow also gets dairy meal or another concentrate, minerals, and often silage or fresh fodder. Decide hay's share of the ration:
- Hay as main roughage, no silage or green feed: about 60% of dry matter from hay.
- Hay with silage or Napier: about 30%.
- Hay only to fill gaps while animals still graze: 10 to 20%.
Step 3: Convert to bales
Take a 450 kg cow fed hay as her main roughage. She needs 13.5 kg of dry matter. Sixty per cent of that is 8.1 kg, which is about 9.2 kg of hay as fed. With 15 kg bales that is just over half a bale a day, or around 18 to 19 bales a month.
Five such cows over a 90-day dry season need about 280 bales. Buying that amount in one or two lorry loads usually costs less per bale than buying a few bales every week.
Add 10% for waste. Even with a good rack, cows pull hay out and stand on it.
Signs you are under-feeding roughage
- Milk butterfat drops
- Cows chew the cud less while lying down
- Dung becomes loose and runny
- Animals bellow or lick at walls and posts
Use the feed calculator on this site to run the numbers for your own herd, then send us the total for a price.
