Is Your Forage Ready for Winter Feeding?

The prolonged hot summer has created two potential challenges for winter feeding: how much forage is available and what that forage will deliver nutritionally.

Some farms are reporting maize silage yields as low as 12 tonnes per acre, around 20% below the normal target of 15 tonnes per acre. At the same time, 2026 second-cut forage analysis indicates lower average energy and fermentable carbohydrate, but higher fibre, than first-cut silages.

Assessing forage stocks and quality now is therefore critical to building an effective winter feeding plan. If forage is in shorter supply or provides less energy than expected, the ration may need to be adjusted to ensure cows receive sufficient energy while maintaining rumen function, health and performance.

As cows move into the winter feeding period, forage stocks should be estimated to establish whether there is enough to feed all livestock until the next harvest, or longer where forage will be needed for buffer feeding. This should include forage requirements for the milking herd, dry cows, heifers and other youngstock.

Simply looking at the volume remaining in the clamp does not provide the full picture. Silage density varies according to dry matter, so the same volume of silage can represent a different quantity of feed from one year to another.

Start by measuring the length of the silage from the back of the clamp to the clamp face, followed by the width and average height:

Volume of silage (m³) = length (m) × width (m) × height (m)

Image description: the clamp measurement diagram.

The dry matter of the silage can then be used to estimate its density. For example, maize silage at 30% DM has an approximate density of 760kg/m³. Multiplying the estimated density by the calculated clamp volume indicates the quantity of silage remaining.

Image description: a line graph showing silage density. 

This can then be divided by livestock numbers and the number of feeding days required to determine the maximum quantity available per head per day. Identifying a potential shortfall now allows farmers and their advisors to build a winter feed plan and establish whether additional forage or concentrates will be required.

Having sufficient forage stocks does not necessarily mean the forage will provide the nutrition required to maintain performance. The hot summer has also had potential implications for forage quality, making analysis an important part of winter ration planning.

The 2026 second-cut forage figures show average metabolisable energy of 10.9 MJ/kg DM, compared with 11.2 MJ/kg DM for first cut, while average NDF has increased from 46.0% to 47.5% DM. There is also considerable variation between individual samples, with second-cut metabolisable energy ranging from 9.1 to 12.1 MJ/kg DM.

Image description: a table showing the 2026 forage analysis.

This variation highlights why winter rations need to be based on the forage actually available on farm. Where forage is lower in energy or higher in fibre, the complete ration may need to be balanced with higher-energy feedstuffs to ensure performance targets can still be achieved.

Where forage stocks are lower than required, reducing forage inclusion may help extend supplies, but the effect on the overall ration must be considered. Reducing the forage-to-concentrate ratio can increase the risk of sub-acute ruminal acidosis (SARA), potentially resulting in poorer rumen efficiency, health and performance.

If forage quantities need to be reduced, alternative feeds should therefore be assessed for the value they provide within the complete ration. Costs should also be compared on a dry matter basis rather than fresh weight, as fresh-weight comparisons can give a misleading picture of the relative cost of different feeds.

Where reduced forage inclusion or high lactic acid loading increases the risk of SARA, Glyco-Buf can be considered as part of the ration to provide multi-phase rumen buffering and help avoid the onset of SARA.

Where forage quality or quantity is putting energy supply under pressure, higher-energy feedstuffs can be used to help balance the ration without disrupting rumen function. However, comparing products on price or headline specifications alone does not show the true value they provide within the ration. The cost of supplementary energy should be calculated using the true energy value of the product, rather than its theoretical energy value, to give a more meaningful comparison of the energy being supplied to the cow.

UFAC offers a range of energy supplements that can be selected based on the available forage and the herd’s nutritional requirements. Envirolac increases dietary energy density while supporting milk yield and milk solids, with the additional benefit of being palm-free. Dynalac combines essential fatty acids to support the energy requirements of high-yielding cows alongside production, health and fertility.

For herds managed as a single milking group, Supa-Cream provides a balanced combination of C16:0 and C18:1 fatty acids alongside omega-3 EPA and DHA and glycerine to support milk yield, composition and fertility throughout lactation. Glycerene provides glycerol that is converted into glucose by the liver, helping to support energy supply where additional glucogenic energy is required.

The appropriate choice will depend on the forage analysis, stage of lactation and the rest of the ration. The focus should be on identifying what the forage provides, where the nutritional shortfall lies, and selecting the most appropriate energy source to address it.

Evaluating forage stocks alongside forage quality provides farmers and their advisors with the information needed to develop a realistic feeding plan for the months ahead. If stocks are insufficient, additional feeds can be considered early. If forage quality is limiting energy supply, the ration can be balanced accordingly.

The aim is not simply to make forage stocks last until the next harvest, but to ensure the ration continues to provide the energy cows need while supporting rumen function, health and performance throughout the winter feeding period.