3 November 1995

CORN COB MIX GOES DUTCH

Corn cob mix offers one Dutch dairy farmer a high starch feed which saves on purchased concentrates. Jessica Buss reports

CORN cob mix is fed to cows on one Dutch dairy unit to increase production from home-grown feeds.

The light sandy soils on the Van Puyenbroek dairy farm, near Tilburg in the south of Holland, grow maize better than grass. The crop has been grown successfully here for over 20 years, claims farm manager Henk van Wyk.

Therefore maize silage makes up most of the forage fed to the 350 Holstein Friesian cows that are housed all year round.

Four years ago the amount of forage maize fed was considered to be at a maximum, but then more land for maize growing became available, he says. The area was increased and the crop harvested for corn cob mix (CCM).

The kernels are harvested using a special header on a forage harvester and are chopped, clamped and sheeted over.

Stems of the plants harvested for CCM are left in the field for chopping and ploughing in. This helps improve the soil structure for the following grass ley, he claims.

The ideal dry matter (DM) for the crop at harvest is around 70%, but this years crop is wetter at about 50% DM.

CCM saves on concentrate and is cheaper to produce, costing the farm 7p/kg of DM in 1994, about 60% of the cost of concentrates at 12p/kg DM, says Mr van Wyk. But this year it cost 14p/kg DM because of lower yields.

All field operations except ploughing are carried out by contractors. The scale of the farm means he is able to negotiate a good price for this work. But the hammer mill the contractors use to chop maize cobs is expensive to buy at about £80,000.

Mr van Wyk manages all the maize crops in the same way. At maturity he pinpoints 75ha (185 acres) for silage and 75ha (185 acres) for CCM. Maize crops are irrigated twice with 40mm (14in) of water in the early stages of growth.

"The CCM produced is a very stable product high in energy and high in starch," says Mr van Wyk. "It is a way of increasing starch in the ration with home-grown products."

He aims to feed 8kg (18lb) of CCM a cow a day in the ration all year round, but insufficient was grown this year due to below average yields. So when none is available maize gluten or maize meal will be fed.

The four groups of cows in the all-year round milking herd are fed the same ration through the whole lactation. There is no grass fed but grass silage is offered to ensure there is enough fibre in the diet, he claims.

Four cuts of grass silage are made and Mr van Wyk aims for a high fibre and low mineral and low lactic acid content. For this reason the silage he produces is not typical of other Dutch milk producers, who cut a less mature, lower fibre crop. &#42