12 March 1999

THE GOLDEN RULES TO GET SILAGE JUST RIGHT

How can you ensure you get

it right every time you

make silage? John Burns

asked one farmer expert

GOOD quality silage is now more important than ever, says Somerset dairy farmer Steve Edmunds, who believes that in a few years time producers will either make good-to-excellent silage or be in trouble.

He says todays lower margins and the national trend to higher yielding cows make it essential to have high quality silage.

Mr Edmunds herd averages 7300 litres at 4.5% fat, 3.5% protein, with 5000 litres coming from forage. Average concentrate use is 0.19kg/litre, at a cost of 2.16p/litre.

The 16.5% average crude protein in his own farm analysis is ideal, he says. "A CP of about 20% can waste the cows energy excreting excess protein, unless there is maize silage in the diet."

Mr Edmunds is convinced that ammonia nitrogen levels in the 1%-3% range are good indicators of so-called super silages which give high intakes, produce good margins, and make the cows really easy to manage because, for example, the absence of acidosis and laminitis.

"One weeks hard work and extra effort at silage making will give you 20 weeks of easier winter work," he says.

He claims he can spot super silages by their bright, sharp colour, the presence of lots of vivid orange pieces, and their very fruity smell.

Mr Edmunds further maintains that unless you are exceedingly unlucky it is possible to make high quality silage every single year, if you follow 11 golden rules.

1 Speed of filling

The one-day clamp is ideal, but good silage can be made over a five-day period if the Dorset-wedge system is used and the temptation to roll the clamp each morning before adding fresh grass is resisted. Such rolling just sucks air into the clamp and makes matters worse, says Mr Edmunds. The main snag with making silage over several days is that the more days it takes the less chance there is of them all being fine.

2 Cover the clamp each night

Sheeting at night helps cut silage losses between clamping and feeding out. The average clamp loses about 25%, or one load in every four put in, but the best silage makers keep losses down to 8%-10%, one load in every 10 or 12. Mr Edmunds advises doing a few loads less a day to leave time to put the sheet on.

3 Compaction by rolling

Adjust extent of rolling according to dry matter of grass coming in. If it is wet, set the forager for a longer chop and do not roll too much. If it is dry or stemmy, or both, chop shorter, spread on the clamp in thin layers and roll well. Ensure good compaction against the clamp walls by keeping the grass higher at the sides than in the middle. Mr Edmunds uses the finger test: In a well-made clamp the opened face is so tight you cannot push a finger in.

4 Wilting to correct dry matter

He suggests a target of 27% DM. "Some producers are going for higher dry matters in the belief they will get higher intakes. But those silages are more difficult to keep stable, particularly during the feeding out period."

For best silage get to the desired 27% DM as fast as possible. Where tedders and rakes are used take care to avoid soil contamination. Some of the most recent equipment for fast wilting is proving effective he says. "If you wanted to make wet silage the best routine would be to mow early in the morning and put several swaths into one."

Most silage machinery is stupid, he says. "It is designed to make foraging easier, not to make good silage." He mows when the dew is off, running two mowers at once – sharing with a neighbour – to cover the necessary area while the standing grass is dry.

5 Sealing quickly and

effectively

Put the plastic on as soon as possible after finishing the clamp. He quotes an old MMB trial in which one of a pair of identical clamps of grass was sheeted immediately and made good silage, while the other was left 16 hours before sheeting and the whole clamp went butyric.

Mr Edmunds says even brand new sheets have tiny holes in them, so he uses side sheets with good top overlaps, then a new top sheet with two or three old sheets on top and all weighted down.

6 Avoid contamination of the grass

Control moles to avoid mole hills. Chain harrowing and rolling are best avoided where stones are not a problem because compaction can cut grass yield by up to 20%. Pressure-wash the clamp and the approach area, and any tractors likely to go on the clamp.

7 Nitrogen content of grass

Too high a nitrate level is the biggest cause of poor silage, says Mr Edmunds. "All the best silage makers I know put on at most 90 units/acre of nitrogen for first cut, 70 units for second cut, and 60 units for third. And they reduce those where slurry has been used."

The old rule of two units a day is too much for first cut, he says. He applies 25kg/ha (20 units/acre) early to keep the grass green and get it away quicker, and puts on the rest when the daffodils are in bud, a reliable guide to soil temperature, he says. Up to 150kg/ha (120 units/acre) could safely be used on Italian ryegrasses, especially in an arable rotation.

"The commonest cause of the different colour bands you see in many clamps is applying the same rate of nitrogen to every field and not allowing for other manures or grass type and field history."

8 Sugar level

This is affected by grass type, season and wilting.

9 Grass quality

The biggest effect of the lot. Mr Edmunds likes a fair proportion of tetraploids in his mixtures. But stage of growth at cutting has a big effect and bad weather can dictate when it can be cut.

Mr Edmunds approach is to regard rules six, seven, eight and nine as the most important. "If any of those is wrong, go for D value and do not worry about the weather. And if one field is wrong, leave it out of the clamp because it will affect the rest."

Pre-cutting sampling and testing for nitrate has merit but when the weather changes, say to wet and warm, which could increase nitrate level quickly, he advises sampling and testing again.

10 Additives

"In general, 50% of additives are a waste of money. And of the other half, only one in 10 times is there a profit on the cost of the additive," Mr Edmunds says. "Adopt a good cynical attitude to additives and you will not go to far wrong."

Nevertheless, he maintains that to make consistent super silage, all 11 golden rules have to be followed, and that means using an additive. He admits that formic acid is good for poor conditions, but under good conditions he goes for the inoculant he invented – Livesystem – which was developed using farmers money.

11 Be prepared

When you aim to start silaging on May 10 make sure that by May 1 all machinery has been serviced, clamps cleaned, and sheets and additives are on the farm. "Then go as soon as the weather forecast looks right." &#42

SILAGE GOLDEN RULES

&#8226 Fast filling.

&#8226 Cover clamp at night.

&#8226 Compaction by rolling.

&#8226 Wilt to correct dry matter – target 27%.

&#8226 Seal clamp quickly and effectively.

&#8226 Avoid contamination.

&#8226 Correct amount of nitrogen fertiliser.

&#8226 Sugar level in grass.

&#8226 Grass quality.

&#8226 Additives.

&#8226 Be prepared.