15 May 1998

Cut your silage grass soon as weather allows

By Sue Rider

GRASS earmarked for silage should be cut as soon as weather allows to safeguard quality, ensuring concentrate savings this winter, and to bring regrowths back into the grazing rotation or for a second cut.

Silage quality will be best in the south of the country, where sugars are already at more than 3.5%, and as high as 4.6% in short-term leys. But digestiblity is starting to fall, and consultants suggest cutting as soon as possible.

Sooner better

"The sooner crops are in the better," advises south-west based ADAS consultant Richard Eaton. D-values have slipped from 73.7 to 72.7 in the last week and will now start falling fast, he says. "The long-term forcast is mainly dry – so go ahead and cut."

He suggests theres no need to use an additive provided the crop is wilted to at least 28% dry matter.

Independent nutrition consultant Pete Kelly also advises cutting as soon as possible. "Italian ryegrass leys sown after maize last autumn are just coming into ear this week and these must be cut."

Silage priority

He suggests priority should be given to silage making rather than maize drilling if a decision must be made between the two.

"Silage quality is deteriorating fast – it will fall by 3-4% a week from now on which equates to 3 litres less a cow at peak yield. So if theres a fine spell, get the silaging done first – a weeks delay in maize harvesting may have no effect at all at the end of the day. And when planting later, soil temperatures may be higher so the crop might catch up, espeically if its a hot, dry summer," he adds.

He forecasts that first cut silage quality will be similar to last year, when grass is cut over the next few days.

"Provided producers get on with cutting now quality should be similar to last year, at 11 ME and 70 D-value."

Silage quality in the Midlands and north-west where the ground and crops are still wet may not be so good, but the advice is the same – get the crop harvested as soon as possible.

"Sugars are still down at 1.5-2%, and because grass grew well early on and then stopped in April, some swards look awful," says Cheshire based Axient business consultant Giles Coley. "Get the crop off and a regrowth coming back into the grazing rotation or for second cut." When crop sugars are low, he advises using an additive.

Little cut

Midlands ADAS consultant Tim Davies says little silage has been cut in his area. "The ground is still wet, as are the crops," he says. Sugars are between 2.5-5%, nitrates low, and proteins 16-26%.

"A few warm sunny days will lift sugars sufficiently for producers to cut with confidence and get a good fermentation." He advises aiming for a rapid wilt to 25-28% dry matter, ideally in less than 24 hours.

Midlands-based Andersons dairy consultant Mike Houghton suggests spreading the grass immediately behind the mower and moving it around as little as possible to achieve a rapid wilt.

"Its easier to manage the grass when its between 25-28% DM and intakes will be higher. But when trying to dry silage, cut at 7-8cm rather than to the ground. Feed value in the last 2-3cm is negligabe and soil contamination risks will be lower if theres a stubblebuffer below the spread grass. "Weve seen higher ash levels as silage DM has risen in the last few years, which is no good for intake."

Longer chop

Mr Houghton also advises aiming for a longer chop length of 2-4cm (0.8-1.5in) where grass is to be fed with maize silage. Hes seen a lot of low butterfats in the Midlands which he attributes to insufficient fibre in the diet.


&#8226 Cut as soon as possible

&#8226 Silage before maize drilling

&#8226 Rapid wilt to 25-28% DM

&#8226 Higher stubble, longer chop


&#8226 Cut as soon as possible.

&#8226 Silage before maize drilling.

&#8226 Rapid wilt to 25-28% DM.

&#8226 Higher stubble, longer chop.