Dry Matter Intake (DMI) is the amount of feed an animal consumes on a dry-weight basis per day, excluding water content. It is expressed in pounds per day. Most forages contain 80–90% dry matter, so actual as-fed amounts will be higher than the DMI figure shown.

Total Digestible Nutrients (TDN) is a measure of the digestible energy in a feed, expressed as a percentage of dry matter. It combines digestible crude protein, crude fiber, nitrogen-free extract, and fat (multiplied by 2.25). Higher TDN values indicate more energy-dense feeds.

Where does the nutritional data come from?

Requirements are based on National Research Council (NRC) publications for each species: Nutrient Requirements of Beef Cattle, Dairy Cattle, Horses, Small Ruminants, and Swine. Values shown are typical averages for the selected body weight and stage and should be refined with a licensed nutritionist for commercial operations.

Why do lactating animals have higher requirements?

Milk production demands significant energy and protein above maintenance levels. A lactating dairy cow can produce 50–100 lb of milk per day, each pound requiring roughly 0.3 Mcal of net energy for lactation. Protein needs increase proportionally to support milk protein synthesis.

Can I use this for commercial feed planning?

This tool provides a starting estimate based on NRC averages. For commercial operations, consult a certified animal nutritionist who can account for specific breed, individual body condition score, actual milk production, forage quality analysis, and local feed prices.

What is the difference between maintenance and growth stage?

Maintenance requirements supply only enough nutrients to sustain body weight and normal physiological functions with no production. Growth requirements add nutrients needed for muscle and skeletal development, resulting in higher DMI, protein, and energy needs per unit of body weight.

Livestock Feed Ration Calculator

Name: Livestock Feed Ration Calculator
Availability: InStock
Author: Nham Vu

Select animal type, enter body weight and production stage to get daily dry matter intake, crude protein, TDN, and energy requirements with recommended feed types.

Animal & Stage

Animal Type

Body Weight (lbs)

Typical range: 800 – 1,600 lbs

Production Stage

Select an animal, enter body weight, choose a stage, then click Calculate Ration.

Calculated!

Summary

Select animal type, enter body weight and production stage to get daily dry matter intake, crude protein, TDN, and energy requirements with recommended feed types.

How it works

Select the animal type: beef cattle, dairy cow, horse, sheep, goat, or pig.
Enter the animal's body weight in pounds.
Choose the production stage: maintenance, growth, lactating, or pregnant.
Click Calculate to generate the daily nutritional requirements.
Review the DMI, crude protein %, TDN %, and energy (Mcal/day) results.
Use the recommended feed types list to plan your ration.

Use cases

Plan daily feed rations for beef cattle at different growth stages.
Estimate supplemental protein and energy needs for lactating dairy cows.
Determine feed requirements for pregnant ewes or does before lambing or kidding.
Balance horse rations for maintenance versus performance needs.
Quickly compare nutritional demands across livestock species on a mixed farm.
Educate agricultural students on NRC-based feed ration concepts.

Frequently Asked Questions

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Last updated: 2026-05-29 · Reviewed by Nham Vu