Advice on winter feeding dairy animals amid forage shortages

Dairy farmers face potential feed deficits this winter as the dry spell continues to hamper grass growth rates.

But it is not to late to bridge those gaps.

Many farmers are feeding first cut silage and with little rain in the forecast successive cuts will be light, warns Will Jones, of Kite Consulting.

The situation across the country is varied, depending on soil type, whether the silage system is multi-cut or traditional and whether the ground has caught the odd shower. But in general there is little grass about, he says.

See also: Complete guide to feeding newborn heifers

“If the rain does come the soil temperatures are warm and grass growth will be good so it may be that farmers can fill their clamps with cuts later into the autumn.’’

Mr Jones and LIC Pasture to Profit farm consultant Piers Badnell caution against leaving it to chance. Here they share their top tips on strategies farmers can take to prevent winter feed shortages.

1. Prepare a forage budget

A forage budget will flag up feed deficits but is often overlooked.

There are several figures that need to be included in the calculation, advises Mr Badnell.

“Work out how much feed you need for the winter, how much has already been eaten, what is needed if the weather is kind or unkind. At least have a plan or some grass cover as insurance.’’

If kilograms of dry matter (DM) are insufficient, alternative sources will need to be bought. But diets must be balanced appropriately to ensure there is adequate fibre to maintain cow health.

Hay, says Mr Jones, provides a good value fibre source, even in the milking ration.

Forage demand planning advice and calculations

  • Need to account for all stock on the farm and estimate the likely DM intake.
  • Number of stock x DMI a head a day (kg) x feeding days / 1000 = Total tonnes (DM).
  • It is important that a safety margin is included (10%)
  • Silage fresh weight required (t) = Total tonnes DM / silage DM % x 100

Forage stocks measurement:

  • Quantity of clamp silage = clamp length x clamp width x clamp height x silage density.
  • The table below can be used as a guide to estimate silage density:

Silage Dry Matter (%)

Clamp height (m)






























Source: Trouw. Note: The guide assumes that grass, maize and wholecrop silages are of similar density for stock estimation purposes

2. Scrutinise the cost effectiveness of winter feed options

Include feeds with adequate NDF – what you include will depend on prices and availability.

Buy forage replacers or purchased feeds on a cost per tonne of dry matter basis, Mr Jones recommends.

Varying amounts of water in feeds make it difficult to compare, which is why it should be done on a DM basis, to establish value for money.

“Speak to a consultant or other adviser to work out which is the most cost effective while also ensuring you supplement what you need nutritionally – the same feeds have different values on different farms,’’ Mr Jones says.

3. Keep on top of grazing management

Crude protein levels in grass could be lower than the normal 20-30%, especially in an organic system, so analyse grass to ensure you are not under-feeding protein.

If you are feeding low levels of grass and supplementing that with silage, analyse the silage for crude protein content.

If necessary, increase concentrate crude protein to achieve the 17-18% required in the diet, Mr Badnell suggests.

He advises against applying nitrogen until it has rained. “Dry soils and dew at night don’t provide sufficient moisture to do any good but when it does rain use nitrogen well to capture growth.

“In an organic situation dirty water will not be enough to ‘irrigate’ but when we have some rain it will supply nitrogen to kick start growth.’’

  • Graze residuals to 1,500kg DM/ha or 3.5-4cm as any brown vegetation will rot when it does rain and will not be eaten, hindering utilisation.
  • Avoid leaving higher residuals to maintain moisture in soils as the benefit is small.

4. Lengthen grazing rounds

Ryegrass is not drought tolerant but there are ways it can be managed to perform in a dry period.

  • Allow the grass plant to grow its third leaf because this represents 45% of yield.
  •  If the round length is too short the plant is grazed below three leaves and potential yield is lost.
  • When lengthening the rotation introduce supplementary feed.
  • Incorporate silage aftermaths to allow the same area to be allocated without additional inputs.
  • Reseed; it works. Farms that reseed 10-15% of the grazing platform annually are seeing the benefit because those reseeds have grown better than old swards and are helping to maintain average covers.
  • If grass has stopped growing, concentrate the cows in one or two paddocks that are due for reseeding and protect the new and most productive swards and allow them to grow to maximum effect when it does rain.

5. Consider limit-feeding heifers

Reducing the amount of feed given to heifers slows down its rate of passage through the rumen and allows the animal to get more value from that feed, but this should only be done with the correct advice.

“If feed stays in the rumen for longer the animal gets more out of it and it reduces the amount you need to give them, but it is dangerous approach if the person managing it is uninformed,’’ says Mr Jones.

Heifers can be restricted to around 80% (that is, 20% less feed). But the system needs to be well managed and adequate feed space provided.

“If feed space is limited there is a danger that some heifers might not get any feed at all. It needs to be done properly,’’ says Mr Jones.

Heifers must also be weighed regularly to ensure the strategy is working.

6. Grow crops for autumn and spring grazing

If some rain does fall in the immediate future, there may be an opportunity to sow quick-growing Italian and Westerwolds varieties to provide grazing in the autumn and spring.

A Westerwold catch crop could go in in August/September and be ready to graze by February if it gets a good start with moisture and not too hard a winter.

Forage brassicas are an option for grazing between October and March. Meanwhile, kale rape hybrids can be drilled in August and, as long as there is moisture, they are ready to graze eight weeks from drilling.