24 March 2000

Combine wrong for grain?

Forage harvesters might be

a better way of harvesting

grain than a combine,

believes one Staffs producer.

Marianne Curtis reports

USING a combine harvester to harvest grain is the wrong move, especially for mixed livestock and arable units.

Replacing it with an adapted forage harvester would reduce grain handling and contracting costs and produce a more suitable feed for livestock.

That is the view of Malcolm Wain of Chatcull Old Hall Farm, Eccleshall, Staffs. Mr Wain farms 220ha (550 acres) consisting of 88ha (220 acres) of winter barley and winter wheat. Leys and permanent pasture account for 122ha (305 acres), supporting a 220-cow, year-round calving dairy herd which averages 6500 litres.

Cows are fed a grass silage based ration supplemented with rolled home-grown cereals, soya and lactose. "My long-term aim is self sufficiency in energy and protein. Heavy, clay land means this is a marginal area for growing maize, so making better use of cereals is important," says Mr Wain.

Cereals are processed through a roller mill which is inefficient, he believes. "Rolling involves moving cereals from grain store to mill, processing at a rate of 4t/hour, twice a week then bucketing cereals into the TMR wagon. It is a slow, dusty job costing about £4-£5/t." A forage harvester – which incorporates a grain processor – could eliminate the need for post-harvest processing, he says.

"Combine harvesters are not ideal for harvesting grain, for two reasons: They are expensive and highly specialised, and they dont process grain ready for use by animals. The compound feed industrys strength has been built on this weakness. With some adaptation, Claass forage harvester can replace the combine and process grain at the point of harvest."

The forage harvester used for harvesting cereals contains a grain processor which can be in position or disengaged depending on whether cereals need to be processed or left intact.

"Traditional methods of whole-cropping produce a feed containing whole grains which can pass undigested through the animal. Also, the high proportion of straw contained in it reduces the energy density from about 13ME for cereal grain to 10-11ME.

"Using a forage harvester with a grain processor means grains can be cracked, improving digestibility." Cutting just crop heads instead of the whole plant also improves energy density, however, this method is less effective than it could be when crop height is uneven, adds Mr Wain.

"Cutting just cereal heads improves energy density. But unless the crop is of an even height – which is rare – including straw will be inevitable to ensure that all heads are harvested. This means energy density is lower than it could be." The ideal option is to use a stripper header which removes grain, chaff and flag leaves, producing a feed with almost the same energy density as cereals, he says.

"Last year we harvested 8ha of wheat and barley using a Claas 860 forage harvester/grain processor with a stripper header attached. But because the stripper header was not designed for this particular machine, there were blockage problems and progress was slow."

The stripper header was also too narrow at 3.9 m (13ft). "To progress with harvesting whole-crop in this way, a properly fitting stripper header with a width of 6-6.6m is needed to avoid damaging land with too many wheelings and for faster throughput.

"Currently manufacturers are unwilling to produce a suitable stripper header. When they do, I will harvest and process all cereals destined for animal feed using the forage harvester. This will eliminate the need for roller milling."

Mr Wain reckons contracting costs would work out at £5/t using the stripper header and forage harvester. Chemicals such as urea – needed to preserve the crop which is harvested at 55% dry matter – cost £5/t. &#42

FORAGE HARVESTER

&#8226 Only harvest cereal grain.

&#8226 Avoid post-harvest processing.

&#8226 More cost-effective use.

Lack of a purpose-built stripper header for the forage harvester meant harvesting cereals was a slow job at Chatcull Old Hall Farm last year.

Malcolm Wain says being able to use a stripper header would improve the energy density of whole-crop silage.