On the majority of livestock farms where cattle will go out to grass in 2024, January is the midway point for the winter housing period.

Therefore, it is an ideal time to complete a fodder budget to see if silage will last until turnout.

The wet autumn forced many farmers into housing earlier than normal. That means cattle have used up more fodder than initially planned, leaving some farmers facing a silage shortage.

The earlier you identify a fodder shortage, the better, as there will be more options to sort it. Don’t leave it until the back wall of the pit is on show.

Plenty of farmers could be looking for silage this spring. This added demand will increase buying prices – and possibly see you miss out.

1. Basic budget

There are three options that can be used to check there is enough silage on farm. The first is simple, but effective and involves assessing the amount of fodder being fed to livestock.

If using bales, how many are being fed each day or week? Count up the number of bales in reserve to get a rough idea of how long silage will last.

If using a clamp, mark the front of the pit face on both side walls with spray paint, or place a block on top of the side wall in line with the pit face.

After one week, re-mark the front of the pit face again. Measure how far back it has moved. Then measure the pit face to the back wall to get an idea of how many weeks the clamp will last.

2. Detailed budget

The second option for fodder budgeting is to use an online calculator, such as the Irish Farmers Journal’s fodder calculator.

Simply input the number of cattle on farm, the number of bales and the size of the clamp to get actual tonnage.

The calculator will then show if there is adequate fodder or a deficit.

3. Manual working

The final option is basically the same as option two, but is calculated manually.

To complete the budget, measure the length, width and average height of the clamp in metres. Multiply the three measurements to get cubic capacity.

To convert this figure to freshweight tonnage, multiply by 0.6 for silage at 30% dry matter, or 0.65 for silage closer to 25% dry matter.

Silage bales will weigh 800kg to 850kg, so count and multiply by 0.8 or 0.85 to get the tonnage. Add this to the quantity of pit silage to get the tonnage of silage on farm. It may be worth deducting 5% to allow for waste forage on the pit and after feeding out.

Stock demand

To work out what cattle will eat, tally up the number of animals on farm across different stock groups for the next three or four months.

Dry spring calving cows will eat 1t/head each month, whereas cows in milk will eat closer to 1.5t/head.

Weanlings and light stores will eat close on 0.75t/ month. Allow an extra month’s forage in case there is a late spring.


If the tonnage of silage exceeds the stock demand, then no action is needed. But if demand exceeds fodder stocks, then take action early to bridge any shortfall in silage.

Options for stretching fodder

Where farmers are running short of forage, what options are available to stretch supplies into late spring?

Given that straw is extremely scarce, sending prices to £220/t, farmers will be reluctant to use it as in previous years to stretch silage stocks.

Ration prices are down £60 to £70/t on last winter, and every 1kg increase in meal will reduce forage intake by around 5kg.

However, the downside to this, other than cost, is that as meal levels increase, the performance response in terms of milk yield or weight gain tails off.


On the flip side, if forage is low quality, there may still be an economic response to feeding higher meal rates to freshly calved cows in milk and finishing cattle.

Having a silage analysis will make it easier to do an economic comparison. Similar comparisons should be made where there are plans to buy in extra forage.

Target lower-quality forage to stores that will go out to grass, as well as dry cows. Keep higher-quality forages for cows in milk and for finishing animals.

Late spring or summer calving cows could be weaned to reduce intakes. The same goes with dairy cows not covering their feed costs in terms of milk output.

That leaves selling off some cattle to reduce silage demand, provided there are no movement restrictions.

With a strong live trade at present, target autumn cows scanning empty, low yielding dairy cows and stores for sale.

Problems with low dry matter silage

First-cut silages harvested from late May to mid-June 2023 should have good dry matter content in around 30%.

However, second- and third-cut forages are likely to have much lower dry matters, as there were limited options to wilt grass before harvesting last summer and autumn.

Wet silage is posing problems on farms and will impact forage stocks. Lower dry matter silages are harder to ferment, resulting in additional waste forage accumulating compared to other years.

Poorly fermented silage will also have palatability issues, reducing cattle intakes and creating more waste silage to scrape out each week.

As rejected silage rates increase, farmers may be burning through the clamp faster than normal due to low dry matter silage.

Where effluent is present, make sure that it is properly collected in storage tanks.

Reduced intakes

Wet silage will also impact cattle performance as animals take in less dry matter, energy and protein with each bite.

That means cattle need to eat more forage, or have meal levels increased, simply to maintain target weight gain or milk yield.

For example, if offered a silage-only diet around 30% dry matter, store cattle weighing 300kg to 400kg will eat 20kg to 30kg/day of forage on a freshweight basis.

But if the silage is reduced to 20% dry matter, the same cattle need to consume 30kg to 40kg/day to achieve the same weight gain.

Such intakes may be physically impossible, especially if silage has a high-fibre content. As such, weight gain will be significantly reduced without introducing meal.

Lower milk yield

Where silage harvesting was delayed last summer, forages will have a reduced energy and protein content, lowering the overall D-Value.

Good silage has a D-Value above 70, but every one-unit drop below this threshold has the potential to reduce milk yield in dairy cows by 0.3 to 0.4 litres/day.

At a consistent 9kg/day of concentrate, cows will yield an extra two litres daily on 70 D-Value silage, compared to average forage at 65 D-Value and four litres more over poor silage at 60 D-Value.

On 100 cows and a milk price of 33p/l, that is an additional £3,960 in monthly milk sales from good to poor quality forage.

As forage quality changes as you move through the clamp, re-test silage to determine feed value and use this information to tweak diets and feed rates to maintain yield.

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