Sorry, I've been traveling a lot lately and not checking StockTalk as often as I would like.

Soybean hay or silage is an option for cows or stockers. It is best when harvested at the R6 stage which is full size green beans - this gives the best combination of tonnage and nutrition.

Beans as grain can be fed, but they contain urease which breaks urea down into ammonia which can reduce intakes and can reduce nitrogen (i.e.protein) metabolism in the rumen. Roasted or extruded beans can be safely fed but add cost. Soybeans (raw, roasted or extruded) have 40% DM protein and a little more energy than corn due to the fat.

Since they are a protein source, I think it's most fair to compare them the DDGs. Energy and dry matter will be about the same, so we can compare them on an as fed basis. Soybeans are 35.2% protein as fed, and DDGs are 25.2% protein as fed. DDGs are costing about 7.5 cents per pound right now. A pound of beans and .4# of corn will replace 1.4# of DDGs nutritionally. 1.4# of DDGs costs 10.5 cents. The .4# of corn is worth 2.3 cents (at $3.20 corn), so the beans are worth 8.2 cents/pound; that makes beans in the ration worth $4.92/bushel when DDGs are $150/ton. On top of that, you should remove urea from the ration which will increase your cost of protein and reduce your rumen efficiency.

Everyones numbers will be different, but I seldom see where soybeans pencil out unless you have damaged beans you can't sell.

I think the soybean silage or hay is the better idea.