With cattle already housed for the winter on many farms, livestock farmers should be reviewing their silage situation, and taking action where necessary.

A significant number of farmers still have second- or third-cut silage to harvest. But even if they do manage to salvage this fodder this month, early housing means they are still facing the possibility of a fodder shortage next spring.

In fact, housing cattle in late August or early September has effectively extended the winter feeding period by two months.

Therefore, it is imperative that farmers take action now to ensure they have enough fodder in store to carry stock through to April of next year.

Leaving the situation until you come close to running out of silage will create bigger problems. But taking early action means you have more options to rectify the situation.

You will also have a better chance of purchasing sufficient fodder, and ensuring it is of average to good quality.

Tonnes of pit silage

So how much silage do you have in the pit? Calculating the volume of silage in store is simple. Measure the length (A) and width (B) of the pit (in feet).

Next, you need to measure the height (C) of the pit face and multiply all three together (AxBxC). To convert to tonnes, divide by 45.

Bales

The weight of silage bales varies depending on the amount of water in the bale and the setting of the baler. A typical 4x4 round bale can vary from 700kg to 1.1t.

Most bales will weigh around the 800kg mark, so assuming a farmer is feeding dry cows eating 25kg to 30kg per day, then one bale will feed approximately 30 cows per day.

Use this as a guide to work out how many bales you have in store and how long they are likely to last this winter.

How much silage do cattle eat?

Table 1 gives an outline of the amount of silage livestock will eat on a monthly basis. To complete a fodder budget, calculate how many cattle you have in each group, the monthly volume of silage consumed and the length of the housing period.

Cull unproductive cows

If you are running tight on silage, there is no point in carrying passengers. For spring-calving herds, scanning now will identify barren cows that can be weaned and sold live immediately.

In addition to empty cows, consider selling off any cows that are nearing the end of their productive life, or causing problems related to bad feet, mastitis, bad temperament or that typically wean light calves.

Prices in the mart are strong, and these cows often cause more issues than they are worth.

For a 50-cow herd with five cows scanning empty, selling these cows now will save up to 30t of silage between now and April.

Trying to purchase the equivalent 30t as baled silage would cost £760, taking an 800kg bale costing £20 each.

Wean early

Where calves are at least 250kg liveweight, they are better off weaned once they are eating meals. Offer calves 2kg/day plus ad-lib silage.

Dry cows can be put on to maintenance silage feeding of 25kg/day, compared with 40kg to 50kg of silage required to support lactation.

In a 50-cow herd, this will save approximately 30t of silage between now and early November, the equivalent of 38 bales of silage.

Restrict suckling

Where calves are too small to wean, restrict suckling to one period in the morning and one in the evening. This will ease the demands placed on the cow and can reduce silage intake by approximately 10kg/day.

Offer straw

Straw has become an expensive commodity this year due to scarcity. But where available, offering 2kg of fresh straw to dry cows will stretch fodder supplies. Some 1kg of straw can replace 5kg to 6kg of silage. Alternatively, for finishing cattle that are eating 7kg to 8kg of concentrate on a daily basis, you could switch from silage to straw.

At high meal levels, silage is merely acting to maintain rumen function and straw will serve a similar purpose. When feeding straw, always ensure cattle are properly covered for minerals.

Sell off cattle

If you are running short on silage, then you may have to sell some cattle to ease the pressure. Only sell cattle that are in a saleable condition. This means cattle that are well fleshed, healthy and at a suitable liveweight to generate a decent sale price. Selling under-fleshed cattle, or animals that are not suited to the live trade (ie strong bulls) will affect buying demand and reduce sale value.

Buying additional silage is generally straightforward, but how do you know what quality of forage you are getting, especially when buying bales? A fodder analysis will give you an indication, but few sellers will have this information. If you are buying-in silage, Do a deal as early as possible – in all likelihood, you could be buying lower quality forage which is only really suited to feeding to dry cows in mid-gestation.

Early purchase means you can use the lower quality silage now for dry cows, saving your best silage to target to finishing cattle, autumn-calving cows or early calving spring cows once they have calved.

Silage or meal

While demand will determine the purchase price for silage, you have to consider at what price is purchasing silage more expensive than buying meal. Silage quality is highly variable. The feed quality often changes as you move across the pit face, or from bale to bale. On the other hand, meal is a consistent feed that will sustain similar performance levels over a prolonged time period.

To compare the feed values of different feeds, you have to do this on a dry matter energy basis as it removes the variation in wet feeds. To be consistent, all prices should be compared relative to the price of dried barley. Therefore, if barley costs £150/t, average quality silage is generally worth £112/t on a dry matter basis.

Assuming silage is 25% dry matter, this makes average quality silage worth no more than £28/t. At 30% dry matter, average quality silage is worth £33/t, while good quality silage is probably worth £3/t more.

If the silage is costing more than the outlined price, then it will be more cost-effective to increase meal levels to cattle.