Dairy Cattle Feed: What It Contains and How to Choose the Right Ration

By Dr Duncan Houston

There is no single standard recipe for dairy cattle feed. A cow grazing good pasture, a high-producing cow eating a mixed ration, and a dry cow approaching calving need different combinations of nutrients.

The feed sold as “dairy pellets” or “dairy meal” is usually only one part of the cow’s diet. Choosing it starts with understanding what the cow already eats and what that diet is missing.

Quick Answer: A typical dairy diet combines forage, such as pasture, hay or silage, with suitable energy feeds, protein sources, minerals and vitamins. Commercial dairy concentrates commonly contain cereal grains, plant protein meals, milling by-products and a mineral premix. Choose a product that complements your forage and suits the cows’ milk production, body condition and stage of lactation.

The first distinction is between a feed supplement and a complete daily ration.

A bag of dairy concentrate generally supplies nutrients to accompany pasture, hay or silage. A protein balancer is intended to be mixed with other feeds at a specified rate. A mineral premix is more concentrated again.

A total mixed ration, or TMR, combines forage and the other ration ingredients into one mixture. A partial mixed ration supplies part of the daily diet, with cows obtaining the remainder elsewhere, commonly through grazing.

Always read the feeding directions. Product names such as “complete dairy feed” can be confusing: establish whether the product is a complete concentrate mixture or is actually formulated to supply the whole diet.

The ingredients commonly used have different jobs:

The proportions matter as much as the ingredient names. Two feeds containing barley and canola meal can have quite different nutritional values. By-products can be useful ingredients, but their composition, moisture and storage quality need checking.

A typical dairy pellet might therefore contain ground cereal grain, canola or soybean meal, milling by-products, molasses and a mineral-vitamin mixture. “Pelleted” describes its physical form, not whether it is suitable for your cows.

Forage remains central to choosing the rest of the ration. Cows need enough suitable fibre to support rumination and normal rumen function. However, fibre quality varies enormously.

Leafy, digestible forage and coarse, mature hay are not nutritionally interchangeable. Straw can supply useful structural fibre in a balanced ration, but it is generally low in energy and protein. Large amounts can limit intake and performance.

A practical feed-selection process follows these steps.

1. Identify which cattle you are feeding.

   Record breed or approximate mature size, milk production, milk fat and protein, body condition, pregnancy status and days since calving.

   Separate the needs of lactating cows, dry cows, cows approaching calving, growing heifers and calves. A ration intended for high-producing milkers should not automatically become the diet for every animal on the property.

   Dry and transition cows need deliberate control of energy and mineral supply. The weeks around calving deserve a specific feeding plan because nutritional mistakes can contribute to metabolic disease.

2. Find out what your existing forage supplies.

   List the pasture, hay and silage available, together with the amounts cows actually consume. Feed offered and feed eaten are different figures.

   Obtain representative forage tests. At minimum, useful results include dry matter, energy, crude protein and fibre. Depending on the feed and ration, mineral analysis, starch and fibre digestibility may also be needed.

   A green colour, pleasant smell or expensive bale does not establish nutritional value. Visual inspection helps identify problems, but it cannot replace laboratory analysis. Retest when a new batch or a noticeable change in forage quality arrives.

3. Choose the supplement that fills the actual gap.

   Good pasture may already supply substantial protein while still leaving a need for additional energy. In that situation, buying the highest-protein concentrate may add unnecessary expense.

   Conversely, a diet based on lower-protein forage may need additional protein as well as energy. Maize silage can contribute substantial energy, but its protein contribution differs considerably from that of legume forage.

   These are starting considerations. The final choice depends on intake and the complete ration, rather than the forage name alone.

4. Read the nutrient specification and feeding directions together.

   Ask the supplier for the product’s intended use, recommended inclusion rate and analysis. Check whether nutrient percentages are reported on an as-fed basis or a dry matter basis before comparing products.

   A feed that looks impressive on paper may supply too little of a nutrient at your actual feeding rate. It may also duplicate minerals already supplied elsewhere.

These are the main figures worth understanding:

Energy, protein, fibre and dry matter are central to evaluating purchased feeds. A dairy nutritionist can interpret them alongside the additional information needed for your herd.

An 18% protein feed is not automatically better than a 16% feed. Those percentages describe the products, not the cows’ entire diets.

Crude protein also includes nitrogen from sources that are not true protein. Some formulated cattle feeds contain urea, which rumen microbes can use under appropriate conditions. It is not nutritionally interchangeable with soybean or canola meal, and it should not be added casually to a homemade mix. The amount, mixing accuracy and balance with other nutrients matter.

1. Compare value after accounting for water and wastage.

   Dry matter is essential when comparing wet and dry feeds. For example, 30 kg of silage containing 35% dry matter supplies 10.5 kg of dry matter. The remaining weight is mostly water.

   Price per delivered tonne can therefore be misleading.

   Using hypothetical prices:

   • Feed A costs $400 per tonne and contains 90% dry matter: approximately $444 per tonne of dry matter.

   • Feed B costs $200 per tonne and contains 30% dry matter: approximately $667 per tonne of dry matter.

   Feed B is cheaper by delivered weight but more expensive per unit of dry matter. That still does not establish which is better: compare the energy, protein or fibre you actually need, then include freight, storage losses and feed refusals. These figures are examples, not current market quotes.

2. Check whether the feed fits your farm’s handling system.

   Consider storage capacity, spoilage risk, delivery frequency, mixing equipment and whether every cow can access the feed.

   A wet by-product may be useful when it can be stored and consumed promptly. The same product can become poor value if it heats, deteriorates or creates excessive waste.

   Check deliveries against the agreed specification and investigate unexpected mould, contamination or deterioration before feeding. Feed purchasing should include a quality check at delivery, not just a price agreement.

3. Introduce changes progressively and measure the response.

   Avoid suddenly increasing cereal grain or changing several major ingredients at once. Wheat and barley starch can ferment rapidly, and excessive intake can destabilise the rumen.

   Ask your adviser for a transition schedule suited to the current ration and proposed change. There is no single safe grain allowance that applies to every dairy cow.

Once a ration is in place, monitor what the cows do with it. Useful observations include:

• Daily feed intake and refusals.

• Milk yield and milk fat and protein trends.

• Cud chewing, appetite and feeding behaviour.

• Manure consistency and undigested feed.

• Body condition over time.

• Feed sorting, competition and access.

A fall in milk fat, loose manure or reduced cud chewing can justify a feeding review, but none diagnoses a ration problem by itself. Interpret the pattern alongside health, weather and management. A correctly formulated ration can still perform poorly if cows cannot access it or selectively leave important ingredients behind.

Water access belongs in every feeding assessment. Cows need clean drinking water throughout the day and night, with enough trough space and refill capacity during peak demand. Requirements rise with milk production and hot weather. Improving the concentrate will achieve little if water supply is limiting intake.

Minerals and additives also need a purpose. Calcium, magnesium, phosphorus, trace minerals and vitamins should be balanced against what the existing feeds supply. Adding several fortified products together can create unnecessary duplication.

Buffers and other additives may help in selected diets, but they cannot compensate for inadequate forage, excessive grain or inconsistent feeding. Ask what problem an additive is intended to solve and how its benefit will be measured.

The common mistakes are choosing on protein percentage alone, treating dairy pellets as the whole diet, comparing wet and dry feeds by delivered weight, and increasing grain without checking the forage and total ration.

A sudden feed-related illness needs a different response from routine ration adjustment. Seek urgent veterinary advice after substantial accidental grain access, or if cows develop severe depression, incoordination, collapse or marked digestive upset. Grain overload can cause life-threatening acidosis. Remove access to the spilled feed and contact your veterinarian rather than waiting to see whether the cow improves.

Some common buying questions have straightforward answers:

• Are dairy pellets better than a grain mix? Either can work. Nutrient balance, quality, processing and correct feeding matter more than appearance.

• Can dairy cows produce milk on pasture alone? Some systems rely heavily on forage. Whether pasture alone meets requirements depends on its quality, intake and the production expected from the cows.

• Can I use the same feed for milking and dry cows? Do not assume so. Dry cows, especially those approaching calving, need a ration designed for that stage.

• How many kilograms of dairy feed should I give each cow? That requires the product specification, forage intake, cow size, milk production and stage of lactation. A bag label is a starting point, not a complete ration calculation.

For a useful comparison between feeds, gather the product labels, forage test results, current feeding amounts and basic herd production records. That allows your veterinarian or dairy nutritionist to identify the nutrient gap and choose a feed that fits it.

ASK A VET™ can help you understand feed terminology and recognise when changes in appetite, body condition or milk production need a closer veterinary assessment.