Making more from maize

Shredlage™, a more aggressive method of processing maize silage has been a success in the US.  Farmers in the UK are now exploring whether the technique will deliver similar benefits here.

Shredlage™ production, a technique developed by Claas, involves a combination of a longer chop length, rolling of the grain to crush the kernel and lengthwise shredding of the stalk.  Typical chop length will be 26-30mm compared to 20-25mm without shredding using a traditional forager.  It is claimed this intensive processing bring a range of benefits.

Trials at the University of Wisconsin showed increased milk yields with typical US diets. One of the reasons for the yield response is the greater chop length and physical processing of the chopped material.  With typical US diets comprising up to 70% maize silage in the forage portion of the diet, the chop length of maize will have a marked effect on overall rumen health.

With 650 dairy cows averaging over 11,200 litres Neil Parkhouse, who farms near Mevagissey in Cornwall, is determined to grow and utilise the most productive forage he can.

He makes around 335 acres on maize silage every year for the all year round housed herd, using a Claas Jaguar 970 forage harvester.  This year he replaced the cracker with a shredlage™ unit.

“Our aim is to make the best quality forage we can,” Neil explains.  “This means growing the best available varieties, focussing on agronomy to produce a good crop and then processing it as effectively as possible so we have a palatable, high quality feed.

“Having read about shredlage™, it seemed to offer us some ways to improve the diet.  If we could improve fibre digestion in the maize, we could potentially remove straw from the diet for high yielders, improving energy density and saving money.”

So this year the entire acreage has been made as shredlage™.  The maize acreage was put down to Limagrain Ambition.  It is one of the Limagrain Animal Nutrition varieties, evaluated for all the key parameters affecting nutritional value, namely starch content and yield, ME content, and yield, CWD, dry matter yield, dry matter percent at harvest and early vigour.

“We were not going to compromise on the quality of the variety grown,” Neil continues.  “Ambition has been a consistent performer and even if the new technique will improve feed value, we still wanted to work from the best start point available with a high energy content and good cell wall digestibility.”

There were no differences to the agronomy compared to traditional silaging.  The crop was drilled in the last week of April, as soon as soil temperatures were adequate.  Harvesting was carried out from 14-20 October.

“We were later finishing than expected because we had a few teething troubles.  We set the unit to chop at 25mm compared to the 21mm chop length we usually use.  We also screwed the cracker down tight to process the cob.  Fuel use was slightly higher but not significantly so.”

Working with nutritionist Alan Moore from ACT, Neil is now learning how best to incorporate the feed into the system.

“On paper there doesn’t appear to be much difference in the analysis,” Alan Moore comments.  “The maize is 41% dry matter, 75.5 D value, 12.1 ME, with 34% starch and a starch degradability of 72%.  The grain is very well processed and evenly spread through the clamp.  It is certainly feeding better than the analysis, with a degradability more like 80%.”

The fresh calver diet is formulated for M+36 litres with an 18% high energy compound fed to yield through out of parlour feeders.  The diets for 2015/16 and the current diet are shown in the table

“We have been looking to increase yield from forage for several years with a focus on forage quality and achieving high forage intakes,” Alan Moore continues.

“With the shredlage™ we hoped to increase forage intakes and save on straw and we have managed to do this, but the biggest surprise was the impact on starch levels.  Despite the later harvesting, the extensive processing of the grain means that the silage is feeding more like a February feed where starch degradability has improved.

“When we introduced the maize we saw a slight fall in butterfats due to too much starch in the diet.  To balance the diet we fine-tuned the proportion of forages with more grass silage and a bit less maize.  We also took out 1kg of akagrain.

“Since making the change butterfats have recovered and the high yield group is still averaging 43.5 litres/day.  We have managed to move the forage concentrate ration from 50:50 last year to 56:44 this year (66:34 in the TMR itself) and feed rate per litre is falling.  Diet presentation is good with little sign of sorting, there is very little rejection and we cows are consuming 27.9kgDM/day.”

Neil Parkhouse is pleased with performance so far, adding that the more vigorous processing appears to be delivering nutritional and financial benefits.  “We have been able to cut out straw as we had hoped and by doing this we will be saving over £2000/month in the value of the straw used and the cost of processing it.  In addition, cutting out the concentrates will save us a similar amount which improving the proportion of forage in the diet and promoting rumen health.

“The extra processing seems to have had benefits on both fibre and starch but I think is still important to start with a high quality variety which will produce a quality feed irrespective of how it is processed, as I don’t think processing alone will turn a poor variety into a good one,” Neil concludes.

Table 1 High yield diets