17 August 2001

Which processing technique?

WITH such a wide range of cereal processing techniques available, which to choose can pose a dilemma for livestock producers.

Speaking to producers at a Keenan Gain from Grain meeting, independent nutrition consultant Hefin Richards outlined choices for cereals. "The best option will depend on animal type, whether there is enough forage and farm storage facilities."

The early harvest of fermented whole-crop makes it attractive, even where maize is the number one option, said Mr Richards. "July harvesting means it is possible to have a grass reseed behind whole-crop."

Poor results when feeding fermented whole-crop in the past were mainly due to harvesting too late, causing a loss in feed value, or feeding insufficient protein to balance the crop, he added.

With urea-treated whole-crop, the main disadvantage is short harvest window, but processed urea-treated whole-crop, also called Alkalage, offers a way around this. "Alkalage extends the harvest window for urea-treated whole-crop from two days to 2-3 weeks, allowing it to be harvested at 65-85% dry matter."

However, care is required when feeding Alkalage at high rates. "Processing the grain means starch is quickly fermented in the rumen. Target DM content of mixed rations should be 40-50%, so add water to avoid a reduction in intake if high quantities of dry Alkalage are being fed, particularly alongside high dry matter silage."

Harvesting whole-crop close to conventional harvest times may also lead to straw shatter, said Mr Richards. "This leads to a reduction in structural fibre in the ration and additional straw may be needed. Straw shorter than 4in is not an effective source of long fibre."

Moving on from whole-crop, Mr Richards also discussed grain treatment options. "Urea treatment provides a way of preserving moist grain using a kinder chemical than propionic acid, while boosting protein.

"But the short harvest window means crimping is usually necessary to avoid faecal grain loss."

Grain for crimping using acids or inoculant preservatives should be harvested at 30-35% moisture, advised Mr Richards. "Harvesting at this moisture content avoids shedding losses and maximises grain yield potential.

"Normal combining is possible, but forward speed should be reduced compared with conventional grain harvesting."

When grain has been crimped it should be possible to squeeze it into a ball. "Harvesting too dry means it is more difficult to exclude air from the clamp, leaving crimped grain susceptible to mould."

For crimped grain, additive costs work out at about £12/t DM and crimping costs £7/t, he added. "Straw can be left to dry before baling or baled and wrapped, allowing it to ferment. Being green, it makes good feeding straw."

Producers opting for BioGrain, which uses an additive to remove the grain coat – making it more digestible – should have plenty of water to hand, said Mr Richards.

"It may be possible to process 10-15t/hour of this grain through a mixer wagon, but you will need 5t/hour of water to do it, so a garden hose wont be up to the job." Additive costs work out at £14/t DM for this option.

Another alternative – soda grain – has become particularly expensive recently, he said. "The cost of caustic soda prills has rocketed in the last 2-3 months. It now costs £11/t to treat wheat and £18/t to treat barley." &#42

TREATEDCEREALS

&#8226 Plan resources.

&#8226 Care over harvest dates.

&#8226 Check costs.