Corn Cob Mix Can Cut Concentrate Costs in Marginal Maize Areas

“Crimping is increasingly being used in more favourable maize growing areas, particularly in the south and south west. The UK area has grown dramatically to around 12,000 ha” he says.  “Here, sufficient heat units enable harvesting of crops to be left up to a month later than those taken for silage,” he explains.

“CCM – which takes the cob and sheath - is a compromise, and can be ready for harvesting 10-14 days after optimum timing for silage.  This brings it in reach of growers on less favourable sites.” Mr Burgess argues that by selecting varieties such as Kaukas, Ohio or extremely early newcomer Lapriora (KXA 5011), growers can take the bulk of their silage at normal timings, ‘reserving’ 10% or so of their crop for a couple of weeks before cutting for CCM.

While a relatively new concept in the UK, CCM is increasingly used as a source of high energy boost in cattle rations in N Germany, Holland and Denmark, reducing the reliance on concentrates. It differs from Ground Ear Maize (GEM) in that a portion of the leaf around the cob is also present in the mix, adding to its scratch factor in the cattle’s diet.

Harvesting is with a traditional forage harvester using a picker header.  Once the cob is fully ripe, the cobs are snapped off the stem and passed through the harvester where they are chopped before being blown into the trailer. The stem and leaves are pulled down through the header and chopped, leaving a mat of stubble on which the machine passes over.  “This provides a thick stubble mulch, minimising erosion risks over-winter,” says Mr Burgess.  “At a time when base fertilizer is almost prohibitively expensive, the discarded stover returns a valuable supply of P and particularly K to soil reserves and the following crop.”

While energy values may not be as high – with ME’s at 13MJ/kg compared to 14.5MJ/kg or so from crimping - CCM is a much more realistic alternative.  Where you would be taking silage at the end of September in a normal year, you’d be back in to cut CCM in mid-Oct, says John.  However, the real advantage of CCM is that in comparison to crimping and maize silage, it provides more fibre and by pass starch in the ration (see table), and this provides a higher rumen scratch value bringing added flexibility and also helping reduce acidosis.

With many farmers now including 70-75% maize silage in rations, there is a real need in today’s diet for a higher fibre source to buffer the rumen.  CCM can provide this at the same time as giving stock a needed energy boost. Agronomically there’s no difference in the management regime for CCM compared to maize silage.  Production costs are similar, the only difference being the additional £2/t or so to ensile.  Crimping however, with it’s need for a second process prior to clamping is at least £20/t more expensive.

While last season would not have been the best to test the process, Mr Burgess points out that farmers could easily have switched their decision and ensiled the whole crop if conditions suggested that harvesting in a fortnight’s time would be problematic.

“Dual purpose maize varieties can offer much greater flexibility, allowing farmers to cut bought in concentrate costs.  Furthermore, because they are grown on farm, under the farm’s management system, they are fully traceable and guaranteed GM-free,” he points out. KWS UK – which is introducing Lapriora (KXA 5011) through Field Options next spring – is looking for growers to test the technique next season.