Forage shortfall

Do you have a forage shortfall?

Some producers are seeing their silage pits emptying and the back coming quicker than they would like, says Piers Badnell, DairyCo technical extension officer. With such wet conditions continuing in some areas, what can you do if you see a forage shortfall appearing?

Hopefully, this silage season will be good and enable the refilling of pits that weren’t replenished fully after last year’s cold winter and spring, and have been put under pressure by this year’s wet conditions. But if you find yourself with a forage shortfall now you can do something about that.

Below are pieces from Adam Clay from Trouw Nutrition, looking at forage substitution, and Chris Duller, independent grassland and soils consultant, looking at eking out remaining forage stocks by getting out to grass when and if possible.

There are also some comments from farmers in Cornwall and Gloucestershire facing forage shortfalls on how they plan to get through the next few weeks, and from a Scottish farmer whose stocks seem to be holding up, for the moment.


Measuring accurately both what forage stock you have and what your requirements are going forwards is key to spotting any shortfalls now or any likely to appear in the future, says Adam Clay, Ruminant Manager at Trouw Nutrition.

Below are some points on forage substitution if, after measuring, you find yourself trying to eke out existing silage stocks:

Balancing dry matter (DM) is key to substitution. Energy and protein levels can be tweaked in the diet, but optimum DM intakes are key. This can be achieved by balancing fibre levels - NDF levels in feed. In order to calculate the quantities needed for substitution of grass silage, and therefore the subsequent cost of that product, you need to divide the NDF of grass silage, about 45, with the NDF of the feed you are thinking of using. For example, if you are thinking of substituting wheat, with an NDF of 12.5, you will need about 3.6 kg DM for every 1 kg DM of grass silage to replace. With sugar beet, with an NDF of 32, you would need 1.4 kg DM to replace every 1 kg DM of grass silage.

So, in reality, substitution is more likely to take place with higher NDF feeds such as palm kernel, sugar beet, soys hulls and wet feeds such as Traffordgold and brewers grains, etc. In general, substitution with these feeds means that the energy density of the diet increases, allowing you to reduce the energy in other feeds.

The alternative is to feed straw - with an NDF of 81% you will need about 0.55kg DM to replace 1kg DM of grass silage. Feeding straw is very useful but you need to keep in mind that it will reduce the energy density of the diet, and this needs to be calculated in the rest of the diet.

Forage substitution can be taken up just by increasing concentrate, but the effect of the increased rapidly fermenting carbohydrate on the rumen must be taken into account, and the rest of the diet adjusted accordingly. Buffering salts or yeasts may be considered to help stabilise rumen function with higher concentrate feeding levels.

If your silage clamp is looking a bit empty and you are looking to substitute some DM intake, look at taking a standard DM intake of around 12kg/day down one or two kgs and replacing them with moist feeds, concentrate or straw to eke out forage supplies until the weather changes. Alternatively, look at buying in big bale silage or haylage if you can. The substitution rate is good, with a high NDF, and the structured fibre content means cows will eat less total DM of forage. The long material means the rumen passage way is slowed down. Although this may be positive for forage stocks it will of course come at a cost to production. Look at feeding a bit more concentrate to help compensate.


With poor ground conditions and low grass growth rates, and the likelihood that cows will still be inside for a few weeks to come, many will be anxiously watching silage stocks, says Independent grassland and soils consultant Chris Duller.

Here are a few strategies to help eke out your feed stocks: 

  • Look at your stock demands – can you reduce the numbers? If you are thinking of getting rid of some barren cows this spring it might worth moving them off the farm sooner rather than later. Look at drying some stock off early.
  • Body condition score – particularly late lactation cows, and target a group of fatter animals that you may be able to tighten feed allocation to.
  • In areas that it’s not too wet it may be possible to graze some fields or even parts of fields.  Walk your ground thoroughly and identify those fields or parts of fields that could take some traffic without too much damage. Electric fence off any wet holes and damaged area. Drop some hardcore in the worst gateways and make multiple access points in your electric fences - ideally one in and one out for every grazing.
  • Get fertiliser on these drier areas – flotation tiers to minimise damage – or even a quad mounted spinner. Urea is the product of choice while there is still the risk of soil water running to drains.
  • Target a small group of cows to graze these driest areas.
  • Short grazing spells – 3hrs – as long as they go out with an appetite they will eat 2-3 kg DM/hour for those three hours. Get them back on the yard by midday – so they don’t just wander around the field and make a mess.
  • Residuals covers are still important but in wet conditions it would be prudent to target 1650 rather than a bare 1500 kg DM/ha. High covers mean a high stocking rate to achieve these residuals, and a high stocking rate equals mess. With light covers of around 2200 stocking rate could be dropped to around 70 cows/ha.
  • Make sure you back fence to stop cows walking on yesterday’s grazed area.

"Just think, 60 cows on a couple of acres, each eating 8 kg DM from grass in a morning -that’s just saved you around 2t of silage," says Chris.


After last year’s late spring, when we completely exhausted out silage supplies, and the cold weather meant slow grass growth we knew we’d be tight with silage stocks this winter, says Cornish dairy farmer Dave Treleaven, who milks 280 autumn block calving cows.

“Last spring, the cold conditions meant we lost that all important early grazing and used up all silage reserves. Add to this a low first cut yield, and when we measured the clamp we could see a forage shortfall appearing. With this in mind we’ve been feeding youngstock on a part straw diet over the winter in an attempt to eke out forage stocks. 

“We have supplemented a bit but the youngstock have done well with the straw in their diets, and they have still hit growth rate targets throughout the winter.

“Although we are ok?? forage at the moment because of the steps we taken, it will be tight and I’ll be getting a little concerned if the weather doesn’t improve. Ironically, in these wet conditions, we are also prone to drought in the summer, so need to have something in the pit to feed out in summer, if necessary.

“We also don’t have great covers at the moment. We had sheep on the land until Christmas and, as the last month has been relatively cold here, any growth we saw over the winter has stagnated.

“Normally, the low yielders would go out at the beginning of March but it looks like we could be a week or two later this year, and that’s even if conditions are drier. We are hoping to get the low yielders out as soon as possible and maybe use remaining forage stocks to look after the higher yielding cows.”


Will Grey milks 130 all year round calving cows, with 100 youngstock, in Gloucestershire and is finding forage stocks pretty tight at the moment.

“I think we’re suffering forage wise from having an organic set-up,” explains Will. “The cold spring last year meant we had less grazing and as we can’t apply nitrogen we couldn’t make up that shortfall in the rest of the season. Then you get yourself into a kind of vicious circle and have less and less forage.

“We would usually hope to have cows out at the beginning of March but the ground is so wet at the moment we’re going to have to hold off. There is plenty of grass, we’ve got good covers, but I know they’d do some real damage out there at the moment.

“We’ve bought in 100 big bales to help with the forage shortage and have looked closely at our culling policy, removing some of the barren cows earlier than might have otherwise gone. We’ve also worked closely with our nutritionist to try to make sure we are providing the best possible diet with the resources available. I’m just keeping my fingers crossed for a good spring grazing period!”


“Unlike many farmers around here who I know are suffering from a lack of forage, we seem to be ok at the moment, we haven’t a shortage,” says Hugh McClymont, Research Farm Manager at Scotland’s Rural College (SRUC) in Dumfries.

“We had an excellent growing season last year, getting four silage cuts off and, in fact, we got five cuts from one field. We have areas of the farm that are just too far away for the cows to travel to, so are not grazed and the grass just kept on growing in these fields.

“Knowing how we were placed, forage wise, after the hard winter of 2012 we just kept putting the grass into big bales and were able to restock supplies.

“We have plenty of grass right now, as a result of the mild winter we’ve had. I’ve got cover of 2,000 kg DM/ha, and that’s with no fertiliser, but we just can’t get the cows out because the conditions are so wet underfoot.  Since 1 December we’ve had 654mm and conditions are just too wet to utilise the grass.

“Obviously we’re keeping a good eye on the weather, and you never know how things pan out - it was about this time last year the really cold weather hit. But just at the moment we’re managing forage wise because of what we were able to put by last summer.”