Sunday, August 31, 2014

Cow math

90lbs of hay = 2.5 cow days
18 cows =  540 cow days per month
= 216 bales a month

6 months of no forage (have to keep the cows off the wet grass so their hooves don't cut up the sod) = 1296 bales, or 58 tons of hay.

figure 3,000 lbs/acre for hay.  38.6 acres of grass to produce 58 tons of hay

Figure 40lbs of corn silage per cow per day = 1200lbs /month
for 20 cows = 24,000lbs/month or 12 tons/month
20 cows for six months = 72 tons of silage
roughly 20 tons of silage per acre of corn
4 acres or corn is the maintenance diet of the cows.

hmmm.. but don't want to run out of food.  Figure 10% for spoilage, and maybe another 20% to have some extra.  Can always sell hay to the horse people....

so I'm using roughly 50 acres to support my 20 cows.


Jeff said...

One thing that looks a bit off is your yield for the hay. I would expect at least 8,000 lbs/acre in normal W. Washington conditions for grass hay. With multiple cuttings, you could get up to 15,000 to 20,000 for the year.

Adam said...

And those 50 acres are producing some GOOD eating!