Convert pounds of feed between as-fed and dry matter (DM) basis — and see what a feed really costs per ton of dry matter.
Use this when a ration, forage test, or nutritionist gives numbers on a dry matter basis but you buy, weigh, and feed on an as-fed basis — or when you compare wet and dry feeds by price.
Silage, haylage, and wet byproducts carry a lot of water. Comparing them to hay or grain only makes sense after both are on a dry matter basis.
Dry matter is the share of the feed that is not water. Multiply as-fed weight by DM% to get dry matter; divide dry matter by DM% to get back to as-fed. Price per ton of DM divides the as-fed price by the DM fraction.
DM_lb = asfed_lb × (DM% ÷ 100)
asfed_lb = DM_lb ÷ (DM% ÷ 100)
$/ton DM = $/ton as-fed ÷ (DM% ÷ 100)
30 lb as-fed corn silage at 35% DM = 30 × 0.35 = 10.5 lb DM.
At $50/ton as-fed, the dry matter costs 50 ÷ 0.35 = $142.86/ton DM. Hay at $120/ton and 88% DM works out to 120 ÷ 0.88 = $136.36/ton DM, so on this example the silage is the cheaper source of dry matter before hauling, storage shrink, and feeding losses.
Reverse: a ration calls for 20 lb DM of the same silage → 20 ÷ 0.35 = 57.1 lb as-fed in the bunk.
Assumptions: one DM% for the whole batch; price is on an as-fed ton of 2,000 lb.
Limits: DM changes with rain, storage, and the face of a silage pile. Dry matter cost alone ignores protein and energy differences between feeds.
Responsibility: use a current forage test and balance rations with a nutritionist or Extension specialist.
From a forage or feed test. Typical ranges are roughly 85–90% for dry hay and grain and about 30–40% for corn silage, but your test is what counts.
Water has no feed value. Two feeds with the same as-fed price can differ a lot in what you pay for the part the animal actually uses.
Yes. The percentage math is unit-free; enter kg and read kg. The price line assumes a 2,000 lb ton.