What is the difference between as-fed and dry-matter basis?

As-fed is the actual weight you scoop, including water. Dry matter removes the water so feeds can be compared fairly. Silage at 35 percent dry matter and dry hay at 88 percent look very different as-fed but are compared on a dry-matter basis, which is how rations are balanced.

What are crude protein and TDN?

Crude protein (CP) estimates total protein from nitrogen content and drives growth, milk, and reproduction. Total digestible nutrients (TDN) is an energy measure, the digestible fraction of a feed. Both are expressed as a percent of dry matter and both must meet the animal's requirement.

How does the tool combine feeds?

It converts each feed's as-fed amount to dry matter, sums dry matter, then weights each feed's CP and TDN by its dry-matter contribution to get the ration's overall CP percent and TDN percent. It compares those to your targets.

What if my ration is short on protein or energy?

Increase the high-CP or high-energy feed, add a supplement such as soybean meal for protein or grain for energy, or reduce a diluting feed like mature grass hay. Adjust amounts until the totals meet both the CP and TDN targets without exceeding dry-matter intake.

Is this a full nutritionist-grade formulation?

No. It balances the two headline nutrients, protein and energy, against intake. A complete ration also balances minerals, vitamins, fiber, and rumen-degradable protein. Use this for planning and rough checks, then consult a nutritionist for production diets.

What is the Livestock Feed Ration Calculator?

Combine feedstuffs from an embedded nutrient database to hit crude protein and energy targets for cattle, sheep, or goats. Shows as-fed and dry-matter amounts plus whether CP and TDN targets are met. Built for producers and consultants. Runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Livestock Feed Ration Calculator

Name: Livestock Feed Ration Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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A balanced ruminant ration has to supply enough protein and energy within the amount of feed the animal will actually eat. This calculator lets you combine common feedstuffs from a built-in nutrient table and instantly see whether the mix meets your crude protein and energy targets on a dry-matter basis.

How it works

Feeds are first put on a level playing field by converting to dry matter, then the nutrient contributions are pooled:

DM of feed   = as-fed lb × (DM% / 100)
ration DM    = sum of all feed DM
ration CP%   = Σ(feed DM × feed CP%) / ration DM
ration TDN%  = Σ(feed DM × feed TDN%) / ration DM

The resulting ration CP percent and TDN percent are compared to the targets you set for the animal, and total dry matter is checked against the daily intake limit so you do not over- or under-feed.

Why dry matter is the foundation of ration balancing

High-moisture feeds like fresh silage or green chop look very different from dry hay when you scoop them, but you’re really feeding the animal the dry fraction that carries the nutrition. Corn silage might be 35 percent DM while grass hay sits at 88 percent — that means 25 lb of silage delivers less DM than 12 lb of hay, even though it weighs twice as much as-fed. Working in DM lets you mix wet and dry feeds in the same ration and compare them fairly.

Worked example — growing beef steer

Suppose you’re feeding a 600 lb growing steer that needs roughly 16 lb of DM per day, 12 percent CP, and 65 percent TDN.

You have on hand:

Corn silage: 35% DM, 8% CP, 70% TDN
Alfalfa hay: 88% DM, 18% CP, 58% TDN

Start with 25 lb of corn silage as-fed:

DM contribution = 25 × 0.35 = 8.75 lb DM

Add 9 lb of alfalfa hay:

DM contribution = 9 × 0.88 = 7.92 lb DM

Ration DM total = 8.75 + 7.92 = 16.67 lb — close to your 16 lb target.

Ration CP = (8.75 × 8 + 7.92 × 18) / 16.67 = (70 + 142.6) / 16.67 = 12.8% CP — above the 12% target.

Ration TDN = (8.75 × 70 + 7.92 × 58) / 16.67 = (612.5 + 459.4) / 16.67 = 64.3% TDN — just under the 65% target.

To close the energy gap, replace 2 lb of the hay with 1.5 lb of shelled corn (88% DM, 8.7% CP, 88% TDN) and re-run. Small adjustments like this are exactly what the tool is designed for.

Practical tips

Use your own forage test results. Book values are averages — actual hay and silage nutrient content varies with cutting date, variety, and storage. A forage analysis from a laboratory is well worth the cost for any diet that must hit precise targets.
Protein and energy aren’t everything. This tool balances the two headline nutrients. A complete ruminant ration also needs fiber (NDF/ADF), calcium, phosphorus, and trace minerals. For lactating dairy cows or fast-growing feedlot cattle, consult a professional nutritionist.
Check dry-matter intake against the animal’s limit. Rumen fill capacity limits how much a ruminant can eat. If the ration DM total exceeds the animal’s dry-matter intake potential, the animal won’t physically eat all of it.