Maize earlage can help producers reduce the requirement for bought-in feed and aid harvesting in difficult autumn conditions. Read on to find out if it could have a place in your dairy system
TEXT FIONA CARRUTHERS
Rising bought-in feed costs means maximising the potential of home-grown forage is under increasing scrutiny on UK dairy units. And for producers already growing and feeding maize, but looking to further increase milk from forage, harvesting a portion of their maize as earlage could offer a solution. So says Corteva’s Chris Woodget, adding that although frequently used in the US and Europe as a high-energy feed, maize earlage is not commonly harvested in the UK. “But producers growing maize could benefit from this flexible harvesting method.
“With a feed value typically falling somewhere between maize silage and maize grain, earlage provides a way of using maize grain without the high drying costs,” he adds.
Earlage is produced by harvesting the ear of the maize plant, using a snapper header, which is then ensiled and fed as a replacement for cereal-based components in the ration, including concentrates or wheat.
“Compared to combining and crimping moist grain, this simple and flexible, single-harvest process makes maize earlage particularly attractive,” explains Mr Woodget. “But it also stacks up nutritionally. As the whole maize ear is harvested, including the spindle and husk, earlage contains good levels of digestible fibre, and provides useful rumen ‘scratch value’ and offers a starch source less inclined to result in acidosis compared to wheat. “Given these benefits, the limited use of maize earlage in the UK is surprising. But, coupled with the substantial increase in fertiliser price, the advantages of producing earlage are clear.”
Producing earlage
For producers thinking of trying earlage, there are a few crucial points to remember, Mr Woodget warns. “Earlage production is best suited to favourable maize growing areas and to maize hybrids – such as Pioneer P7326, P7034 and P7948 – that have the necessary agronomic characteristics,” he says. “Look for hybrids with a high grain yield, no tendency to drop ears and that can reach full grain maturity. Good root strength and high levels of resistance to stem fusarium to prevent lodging are also important.” Earlage harvest is typically a couple of weeks later than maize silage, with the husks becoming straw like in colour and kernels reaching ‘black layer’ stage. The ideal harvest maturity is between 58% and 64% dry matter. Timing is crucial because higher dry matter reduces digestibility.
Hybrid maize: look for varieties that can reach full grain maturity
“Machinery adjustment and set up is also important,” adds Mr Woodget. “The maize ears should all be snapped off cleanly and the kernels well processed. The husk should also be sufficiently chopped and shredded to avoid long strands and the risk of ration sorting. All kernels should be cracked and pieces of spindle should be no larger than a thumbnail.
“After harvesting, ensile earlage in a well-sealed clamp. As with all silages, be sure to consolidate well to expel air, and also consider using a silage inoculant to enhance fermentation and reduce clamp shrinkage and heating during feed out.”
Mr Woodget adds that it’s important to analyse earlage regularly during feed out because rumen starch digestibility increases while the crop is in the clamp.
Supporting yields
Brothers Mike and Chris King run Kingspool Holsteins, at Iron Acton near Bristol, and started harvesting maize earlage for the first time in 2021. “We grow around 243 hectares of maize each year, a proportion of which we usually combine,” says Mike.
“But difficult autumn weather conditions and poor combine availability led us to look at alternatives. A local contractor had access to a snapper header, so we decided to try 22 hectares of maize earlage.” Alongside grass silage and cereals, maize silage forms an important part of the ration for the all-year-round calving 700-cow herd. Producing an average yield of 13,320 litres at 3.72% butterfat and 3.31% protein, they supply Müller on an M&S contract. “Our aim is to be a high-yielding, high-welfare herd with a low environmental impact. But, as much as environmental sustainability is important, we also need to be productive and profitable. We limit our bought-in bulk feeds to rape meal, and focus on making the most of home-grown forage,” says Mike.
This makes the feed value of maize earlage particularly useful. The Kings used it to replace soda wheat in the ration, at a rate of 4kg per head, and within a month yields had increased by 0.9 litres per cow. “The cows took to it well with no sorting, so we increased the amount in the ration as it matured in the clamp,” says Mike.
The brothers grew two maize hybrids, P7034 and P7892, on free-draining, light soil and found both varieties performed well. Harvesting began in October achieving more than 17 tonnes per hectare at 55% dry matter and 61% starch. Silage analysis on the high starch digestibility hybrid P7034 show crude protein at 8.2%, starch at 60.9%, starch digestibility at 80.2%, and NDF at 19%.
“Producing maize earlage has worked well for us so we’re planning to grow more, a total of 40 hectares, this year,” says Mike. “We’ve learnt that choosing the site carefully is important to avoid the risk of soil damage during challenging conditions. We’ve also found having a longer, narrower clamp keeps the clamp face tight and avoids the risk of secondary heating, particularly if feeding out early.”