Free TMR Calculator
dry matter intake (DMI) & water requirement.
Estimate daily Dry Matter Intake (DMI), as-fed ration weight and drinking water for Holstein, Jersey, Sahiwal and water buffaloes. Feeding to a realistic intake helps reduce the risk of Subacute Rumen Acidosis (SARA) and supports feed efficiency.
TMR Dry Matter Intake & Hydration Estimator
Adjusted for 4% Fat-Corrected Milk (FCM) and heat-stress water demand.
Want to check the whole ration, not just intake?
Our free ration balancer analyses your own mix of corn silage, Rhodes grass, wheat straw, cottonseed and concentrates against NRC-based nutrient requirements, with feed cost per day.
Principles of Precision TMR Formulation
Why Dry Matter Intake is the master variable governing dairy production and metabolic health.
Dry Matter Intake (DMI) Rules
A ration is balanced on its dry matter, not on the wet weight of feed. To supply the same dry matter, a cow needs about 2.5 times as much wet corn silage (35% DM) by weight as dry concentrate wanda (90% DM).
- Target DMI: 3.2%–3.8% of body weight for high-producing cows.
- Water Buffaloes: Usually lower than high-yielding cows, often about 2.5%–3% of body weight.
- NDF Threshold: NRC (2001) suggests at least 25% NDF in the ration dry matter, with enough of it (about 19% of DM) coming from forage, to help reduce SARA risk.
Heat Stress & Water
From about 25–27°C (77–81°F), and lower in humid weather, high-yielding cows start to feel heat stress. They drink more water to help them cool down, and dry matter intake often falls by 10%–20% or more.
- Water Intake: Water needs rise with milk yield, feed intake and heat. Keep clean water available at all times, with enough trough space for several animals to drink at once.
- Night Feeding: Feed more of the daily ration in the cooler evening and night hours, and push feed up often.
- Buffers: Ask your nutritionist whether to add a rumen buffer such as sodium bicarbonate in hot weather, and at what rate.
How to use this calculator
- Pick the breed profile closest to your animals. It fills in a typical body weight, milk yield and butterfat, which you can then change.
- Enter the body weight, daily milk yield and milk butterfat % for your cow or buffalo. Use recent figures from your milk records or a milk test if you have them.
- Enter the usual daytime temperature in the shed.
- Read the three results. They update as you type, so you can see how a change in yield or hot weather affects them.
Reading the result
Dry matter intake (DMI) is how much feed the animal is expected to eat each day with the water taken out; it is the figure to balance a ration on. The as-fed figure turns it into the weight of mixed ration per animal per day, assuming the mix is 50% dry matter. If your mix is wetter, divide the DMI by its dry matter instead: 20 kg of DMI in a 40% dry matter mix is 50 kg as fed. Multiply by the number of animals to size a batch. Above 27°C (81°F) the calculator lowers intake for heat stress, and above 25°C (77°F) it raises the water estimate. The water figure is a generous planning figure for sizing troughs and water supply; many cows drink less. These are planning estimates; your nutritionist can check them against what your animals actually eat.
Common questions about feed and water intake
How much dairy cows eat and drink, and how far the estimates apply to buffaloes.
How much dry matter does a dairy cow eat per day?
Most milking cows eat roughly 3–4% of their body weight as dry matter each day. High-yielding cows are at the top of that range; fresh cows and cows in hot weather eat less. Any formula is an estimate, so weigh the feed offered and the feed left over to see what your cows really eat.
How much water does a milking cow drink per day?
It depends mainly on milk yield, feed intake and temperature. A high-yielding cow can drink well over 100 litres (about 26 US gallons) a day, and much more in hot weather. Cows drink a lot straight after milking, so make sure clean water is easy to reach as they leave the parlour, with enough trough space for several cows to drink at once.
Does this calculator work for buffaloes?
The intake formula was developed for dairy cattle. The buffalo profiles give a starting point, but buffaloes usually eat less dry matter per kg of body weight than high-yielding cows, so check the ration with your nutritionist.
Decision support only. Not a substitute for your veterinarian.