Crimpled Grain Maize should push up yield:By Debbie James
GROWING A CROP of maize only to plough in stems and leaves may sound criminal to many milk producers, but its Pembrokeshire growers believe the value will be in the harvested and crimped grain.
They may not be in the UK’s most favourable maize growing area, but Michael and Gwyn Roblin were keen to experiment with grain maize because of its potential to increase milk and milk protein yields.
They reckon the feed could push up milk yields by 1000 litres a cow and reduce concentrate costs. Nearly half the starch in maize grain bypasses the rumen, allowing slower rates of digestion and high intakes with minimal acidosis risks.
Their 200 cow all-year-round calving herd at Clynderwen and Glynty Farms averages 7200 litres, with 3400 litres produced from forage. Milk is 4.1% fat and 3.44% protein.
Maize grain will provide a high energy feed for the herd. “It is an experiment this year, but if it works well and costs are comparable with bought-in concentrates we will grow it again,” says Gwyn Roblin.
The 8.5ha (21 acre) grain maize crop yielded nearly 13.6t/ha (5.5t/acre) fresh or 9.5t/ha of dry matter (3.8t/acre). A crop of wheat would have averaged 5-7t/ha (2-2.8t/acre) and the feed value would not have been as good, adds Mr Roblin.
From seed to ensiled grain, the maize crop, grown under plastic, cost £430/ha (£180/acre). Growing it under plastic added £136/ha (£55/acre) to the costs, but was essential to achieve the necessary stage of maturity to harvest in October. But the brothers are confident they will get a payback from the high starch content – in this case 65%.
The grain maize will be used to replace concentrate in the winter ration and not forage. Forage maize will also be fed, with half of each cow”s daily diet coming from grass and maize silage. The total mixed ration will also include 1kg each of soya, crimped barley and straw for fibre.
Mr Roblin says reduced costs will come from replacing some of the 9kg of concentrates fed in the parlour with 2-3kg of maize grain.
Ideally, for maximum feed value, maize should have been left standing for another week, but with rain forecast they were advised not to wait. It was harvested with a specialist Cressoni header fitted to the Roblins” own combine harvester.
Andy Strzelecki, technical director for Kelvin Cave which supplied the header, reckons drilling the crop three weeks earlier would have achieved an earlier maturity. The crop was drilled on Apr 22, but experiments in Ireland achieved success with crops planted on Mar 17, he explains.
“We had a hold up with the drills and plastic, but if we grow it next year we will drill it in March,” says Mr Roblin.
The crop had reached such an advanced state of maturity that there was no feed value in the forage. But there was always the option of harvesting the crop as maize silage earlier if the farm was short of forage.
He also stresses that maize grain is not a replacement for maize silage. “Producers must address their forage needs first. This crop does not compete with maize silage, but with concentrate feed imported onto the farm.”
A typical analysis of crimped maize grain shows a dry matter of 67-70%, crude protein of 9.5-10.5% and a metabolisable energy content of 14-14.5MJ/kg.