Free Dairy Feed Formulation Software
CNCPS-informed ration balancing & nutrient evaluation.
Dairy nutrition decision support for herd managers, nutritionists, and dairy producers. Balance Dry Matter Intake (DMI), carbohydrate fractions (sugar, starch, peNDF), RDP/RUP bypass protein, and amino acids. Works in kilograms, with feed prices in your own currency (PKR, USD, GBP and more).
Feeding a Whole Herd?
The Herd Manager app adds ration analysis against NRC-based nutrient requirements to your farm records, with per-pen feeding plans that draw down your feed stock, low-stock and expiry alerts, and each pen's feed cost per litre of milk.
How CNCPS-style Feed Fractions Work
Why splitting carbohydrate and protein by how fast they break down in the rumen gives a clearer picture than crude protein and TDN alone.
Dynamic Carbohydrate Fractions
The CNCPS approach splits total carbohydrate by how fast it ferments in the rumen:
- CHO A (Sugars & Organic Acids): Rapidly fermenting pool (200–300%/hr) driving early microbial energetic surge.
- CHO B1 (Starch): Intermediate pool (20–40%/hr); balanced to support peak milk without triggering rumen acidosis.
- CHO B2 (Digestible NDF): Slowly fermenting fiber (3–8%/hr) providing sustained acetate for milk fat synthesis.
- CHO C (Indigestible NDF / ADL × 2.4): Rumen filler regulating passage rate and physical gut fill.
Protein Pools: RDP vs. RUP
Rumen microbes require ammonia and peptides, while high-producing mammary glands require post-ruminal absorbable amino acids:
- Fraction A (NPN / Soluble Protein): Rapidly degraded into ammonia in the rumen.
- Fraction B (True Protein): Degraded at intermediate rates (B1, B2, B3) yielding Rumen Degradable Protein (RDP).
- Rumen Undegradable Protein (RUP / Bypass): Escapes rumen fermentation intact to be digested in the abomasum and small intestine.
- Microbial Crude Protein (MCP): The highest biological value amino acid source for lactating cattle.
Physically Effective Fiber (peNDF)
Chemical NDF alone is insufficient to prevent Subacute Ruminal Acidosis (SARA). Particle length and chewing stimulation dictate buffering:
- Minimum Target: 21% to 23% peNDF of total ration Dry Matter.
- Salivation Factor: Chewing long forage particles stimulates sodium bicarbonate secretion in saliva.
- Rumen Mat Formation: Traps smaller concentrate particles for complete bacterial fermentation.
How to use this calculator
- In the Cow step, describe the animal: body weight, lactation number, days in milk and body condition score, then daily milk yield with its fat and protein %. Mark her as pregnant and set the month if she is, and enter the shed temperature and humidity. Leave Actual DMI at 0 to use the predicted intake, or enter what she really eats if you weigh it.
- In the Ration step, add feeds from the library (search by name or filter by category), or press Load starter ration for an editable example. Enter the as-fed kg of each feed per cow per day and its price per kg, after choosing your currency. Use Edit on any feed to replace the library values with your own forage test results.
- Open Analysis to compare what the ration supplies with what the cow needs, nutrient by nutrient. Adjust the kg in the Ration step and check again.
- Open Insights to see each shortfall or excess explained, and save the ration in this browser. Use Print or Export at the top of the workspace to keep a copy, and Import to restore one.
Reading the result
Each nutrient in the Analysis step is marked OK, Caution, Deficient or Excess by comparing the ration's supply with the modelled requirement for the cow you described. Work through them in order: dry matter intake and energy first, then protein (RDP, RUP and metabolizable protein), then fibre (NDF, forage NDF and peNDF) and the estimated rumen pH, and only then minerals, vitamins and amino acids. A Caution flag means the ration is close to a limit, not that it is necessarily wrong. The ration cost is per cow per day at the prices you entered. Library values are typical figures, so a ration that looks balanced here still needs checking against your own forage analysis and how the cows actually respond in milk, manure and body condition, and reviewing with a nutritionist before you change what the herd is fed.
Using the Workspace in Your Region
The model works in metric units everywhere. Pick your currency in the ration builder and enter your own feed prices.
United States & Americas
Enter weights in kilograms (1 lb = 0.4536 kg). Energy is shown as NEL in Mcal/kg. Choose USD and type your feed prices per kg. Corn silage and alfalfa hay and silage are in the feed library. Check their values against your own forage tests.
United Kingdom & Europe
Energy is shown as NEL in Mcal/kg, not ME in MJ/kg (1 Mcal = 4.184 MJ). Choose GBP or EUR and type your feed prices per kg. Grass and ryegrass silage values vary a lot between cuts, so use your own silage analysis.
Pakistan & South Asia
The sample feed prices are Pakistani market rates in PKR. Update them to today's prices. The library includes canola meal, cottonseed, and wheat bran. Milk fat input goes up to 6.5%, so treat results for high-fat buffalo milk as approximate.
Common questions about CNCPS ration balancing
Answers to technical questions regarding dairy cattle ration balancing and nutrient evaluation.
What is CNCPS dairy feed formulation?
The Cornell Net Carbohydrate and Protein System (CNCPS) is a mechanistic model that looks at how fast feeds ferment in the rumen, passage rates, microbial growth, and amino acid digestion in the intestine, rather than relying only on crude protein from feed tables.
Is this the official Cornell CNCPS software?
No. This is a simplified, CNCPS-informed tool built by Herd Manager from published research. It uses the same idea of carbohydrate and protein fractions but is not the CNCPS software and does not replace a full ration program or a nutritionist.
What is the ideal RDP to RUP ratio in lactating dairy rations?
A high-producing dairy cow ration typically targets approximately 60% to 65% Rumen Degradable Protein (RDP) to maximize microbial protein synthesis, paired with 35% to 40% Rumen Undegradable Protein (RUP / bypass protein) to supply essential amino acids directly to the small intestine.
How much Dry Matter Intake (DMI) should a 1,400 lb (635 kg) Holstein cow consume?
A lactating Holstein producing 75–85 lbs (34–38 kg) of milk typically consumes between 3.6% and 4.2% of her body weight in Dry Matter daily, equating to approximately 50 to 58 lbs (23 to 26 kg) of DM per day.
Is this dairy ration formulation tool free?
Yes. The ration balancer on this page is free to use in your web browser, with no account and no software to install. You can balance rations, check the CNCPS-informed nutrient fractions, and print or export your results.
Can I save, print, and export rations without creating an account?
Yes. The public tool saves your working ration draft in your own web browser, lets you export and import backup files, and prints a summary report (which most browsers can also save as a PDF), all without a login.
About the model: Nutrient calculations are based on published, peer-reviewed research, including the NRC Nutrient Requirements of Dairy Cattle (2001), NASEM (2021), and CNCPS literature (Fox et al.; Sniffen et al.). Herd Manager is an independent platform and is not affiliated with, sponsored by, or endorsed by Cornell University. Results are estimates and should be checked against forage analysis and reviewed by a qualified nutritionist.
Decision support only. Not a substitute for your veterinarian.