5 ways to get more from your maize silage

Make every tonne of maize silage count

Maize silage is a valuable foundation for dairy rations, providing a homegrown source of starch and energy to support milk production. But the nutritional value of every clamp will differ, with growing conditions, maturity at harvest and fermentation all influencing silage quality and starch availability. For example, ForFarmers' 2025 analysis reported that average starch levels in its maize silage samples were 30.3% in 2022 and 27.6% in 2024.

Understanding exactly what your maize is supplying is just the starting point for building a balanced ration. From choosing complementary energy sources to maintaining rumen function, several factors can influence how effectively cows utilise the forage you've grown.

We’ve identified five practical considerations to help you make the most of your maize silage while supporting herd performance.

1. Know what your maize is delivering

The first step towards getting more from your maize is knowing what's actually in the clamp.

Regular forage analysis provides a more reliable basis for feeding decisions than relying on typical maize values or previous years' results. Key measures including dry matter, metabolisable energy, starch and digestibility can help build a clearer picture of the silage's feeding value.

Analysis shouldn't stop with the initial sample either. AHDB recommends continuing to test maize silage from the clamp face throughout the feeding season, as its feed value can continue to change after harvest.

With a clearer understanding of what your maize supplies, you can formulate the remaining ration around it, identifying where additional energy may be needed. Different feed ingredients contribute energy in different ways, making the choice of complementary ingredients an important part of ration formulation.

2. Don't automatically reach for more starch

If your maize silage isn't providing enough energy to meet herd requirements, increasing cereal inclusion may seem like the straightforward solution. However, the source of that energy can be just as important as the quantity supplied.

Cereal grains like wheat and barley contain rapidly fermentable starch, which increases acid production as it breaks down in the rumen. If acid production exceeds the rumen's ability to buffer and absorb it, pH can fall, reducing fibre digestion and increasing the risk of subacute ruminal acidosis. Relying too heavily on rapidly fermentable starch can also increase the risk of milk fat depression.

Maintaining a healthy rumen environment becomes an important consideration when addressing an energy shortfall. Rather than relying on additional cereal starch alone, consider how alternative energy sources, including dietary fat, can complement the ration while supporting rumen function and milk production.

3. Consider the overall balance of the ration

Digestible fibre sources such as soya hulls, citrus pulp and sugar beet pulp can play a useful role in maize-based diets. They provide an alternative energy source to cereal starch, helping to balance the ration while supporting rumen function and milk fat production.

But there are practical limits to how much can be included. Compared with more concentrated energy sources, digestible fibre ingredients have a lower energy density and greater bulk. Increasing their inclusion too far can lead to physical rumen fill becoming a limiting factor, restricting how much feed cows can consume and, in turn, their total energy intake.

The aim is to find the right combination of ingredients to complement the maize silage without compromising overall energy supply. For high-yielding cows in particular, this means considering how much energy the ration can deliver within the volume of feed they're able to eat.

4. Increase energy density without adding to the acid load

When cows need more energy than the existing ration can comfortably supply, rumen-protected fats offer a way to increase energy density without adding more fermentable starch or bulky ingredients.

Fat is the most energy-dense nutrient available to dairy cows, supplying more than 2.5 times the energy density of cereals. Even at relatively small inclusion rates, it can make a meaningful difference to the energy available within the ration. For example, adding 500g of Megalac can increase dietary energy density by approximately 0.5 MJ/kg DM.

Unlike cereal starch, rumen-protected fats undergo minimal breakdown in the rumen, allowing fatty acids to pass through to the small intestine for digestion and absorption. This provides an additional source of concentrated energy without increasing the rumen's fermentation acid load, making them a useful complement to maize-based diets.

5. Match the fatty acids to what you want from the cow

Increasing dietary energy is one consideration when choosing a fat supplement, but its fatty acid profile can also influence how that energy is used. Different fatty acids support different production objectives, making the cow's stage of lactation an important factor in deciding what to feed.

Early lactation

During the first 120 days after calving, maintaining energy supply while limiting excessive body condition loss is particularly important. Supplements supplying oleic acid (C18:1) can improve total diet fat digestibility and help direct nutrients towards body condition. C18:1 also plays a role in supporting egg and embryo development, making it relevant to nutritional strategies focused on subsequent fertility.

Later lactation

Once cows move beyond peak lactation or are back in calf, the nutritional priorities may shift. Supplements higher in palmitic acid (C16:0) can help direct more nutrients towards milk and milk fat production, particularly where increasing milk solids is a key objective.

Choosing the right fat supplement for each stage of lactation enables you to target the response you want from the cow while making better use of the energy supplied by the wider ration.

Get more nutritional value from the maize you've grown

Making the most of homegrown maize starts with understanding its nutritional value and building a ration that complements what it supplies. Adding more starch may increase energy availability, but maintaining the right balance of energy sources is equally important for protecting rumen function and supporting herd performance.

Where additional energy is needed, rumen-protected fats offer a useful way to complement maize silage, with fatty acid profiles selected to suit the cow's stage of lactation and production goals.

With the right balance, you can get more from the forage you've grown while supporting milk production, milk solids, body condition and fertility throughout lactation.

For further advice on optimising your maize-based ration, explore our technical resources or get in touch with your nutritionist to discuss the most suitable fat supplementation strategy for your herd.

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