Winter feed
Hay calculator for cattle
Count the bales before the first frost, with the waste you really have at the feeder.
Hay needed = head × body weight × daily intake × days on hay, divided by the hay’s dry matter and by the share that is not wasted. Fifty 1,300 lb cows eating 2.2% of body weight for 120 days need 171,600 lb of dry matter. At 88% dry matter and 12% feeder waste that is about 111 tons of hay, or 185 bales of 1,200 lb.
Example numbers. Change them to your own.
Choosing the inputs
- Daily intake. Cows in Oklahoma State University feeder trials ate 1.8% to 2.5% of their body weight in hay dry matter per day. Lactating cows and better hay sit toward the top of that range.
- Dry matter. Use the figure from your forage test. The 88% here is an example.
- Feeder waste. In the trials summarized by Oklahoma State, open ring feeders wasted about 20% of the hay, sheeted rings about 12% and sheeted basket (cone) feeders about 5%.
- Bale weight. Weigh a few bales. Weight changes with the baler, the forage and the moisture.
- Days on hay. The calculator only knows the days you give it. Add days for a late spring.
How many round bales does a cow need for winter?
It depends on her weight, the days on hay, bale weight and waste. A 1,300 lb cow eating 2.2% of body weight for 120 days, with 88% dry matter hay and 12% waste, needs about 4,430 lb of hay, or 3.7 bales of 1,200 lb.
How much hay does a cow eat per day?
Cows in Oklahoma State University feeder trials ate 1.8% to 2.5% of body weight in hay dry matter per day. For a 1,300 lb cow at 2.2%, that is about 29 lb of dry matter, or about 33 lb of hay at 88% dry matter, before waste.
How much hay do cattle waste?
It depends on the feeder. In trials summarized by Oklahoma State University Extension (fact sheet ANSI-9413), open ring feeders wasted about 20% of the hay, sheeted ring feeders about 12% and sheeted basket feeders about 5%.