Cut early and wilt fast

Cutting earlier, before the grass approaches heading, will reduce yield, but protein, digestibility and metabolisable energy (ME) all increase. This will support greater milk production, while a lighter crop will have less losses in the field.

A rapid wilt is also a must. As soon as grass is cut, sugars start to decline as they are being used by the plant, which is still living, and also by undesirable bacteria. This raises the pressure to get it in the clamp quickly. Wilting also increases the dry matter percentage and reduces clamp losses from effluent.

Mr Ward says there is a twohour window for producers to take advantage of in order to get an efficient wilt. This is the time when the stomata on the plant remain open and water loss is at its greatest; about 100 litres/tonne of grass every hour. After that, water is only lost where the leaves are broken or where the crop has been conditioned – if a conditioner has been used.

“Ideally the mower and the tedder should be in the field at the same time, or at least within two hours of each other,” says Mr Ward. This will ensure a rapid wilt is achieved.

This is particularly important with an early first cut, where weather conditions may not be ideal. Water loss will be highest when air moves over the crop, so ‘flicking the crop up’ with the tedder will aid evaporation. Leaving a 5-6cm stubble will also help lift the crop off the ground and expose it to air movement.

Producers should also take a step back and ask themselves if they could adopt a multi-cut silage system.

Can I do a multi-cut system?

The multi-cut system reduces the time between cuts from the traditional six weeks to about four weeks. This means more than three cuts are taken in the year, with some producers taking five-six. First cut is also taken earlier than traditional methods (see Silage-making strategies compared panel).

“It’s traditional as it’s the way we’ve always done it,” adds Mr Ward. “That alludes to the fact we haven’t really challenged what what we’ve done. Multi-cut challenges that.”

By cutting more frequently on a multi-cut system, grass is younger and leafier and of greater digestibility. This encourages forage dry matter intakes and provides the potential to displace bought-in feed.

Mr Ward believes multi-cut is one of the ways producers can boost milk from forage figures and thus MOPF, while growing more nutrients off the same acreage.

“Multi-cut is a way to exploit more from grass and to get the physical and financial benefit from it,” he says.

Although the individual cuts may be lighter – perhaps 1.6-2t/hectare (4-5t/acre) at first cut versus 3.2-4t/hectare (8-10t/acre) on a traditional system – the total dry matter yield produced through the
season is likely to be the same or more. Most notably, the quality of silage produced will be much higher (see Table 2).

ME increase

A 1MJ/kg DM increase in ME is generally recognised from moving from a traditional to multi-cut strategy. This will support milk production and also ‘more than pay’ for the extra contracting costs from cutting more frequently (see Table 1).

Mr Ward says improved silage quality equates to a 2ppl saving in feed costs, as a result of higher forage dry matter intakes and having to buy-in less energy and protein. However, there are some key things to think about when taking a multi-cut approach (see multi-cut – key considerations panel).

Mr Ward believes multi-cut is something which should be considered on many farms. However, there are some situations where it is not possible; namely if it is not possible to get contractors to cut frequently or where the farm’s location means weather is challenging.

“Where geography, weather and management means you can’t achieve multi-cut, then traditional silage-making is for you. But challenge yourself to see if you can go early,” Mr Ward adds.

Case study: Jason Bayley – multi-cut silage

Jason Bayley’s multi-cut silage system is all about maximising the production of energy per hectare to enable costly bought-in feeds to be displaced by quality, homegrown forage.

He says: “Our forage is treated almost like a concentrate, rather than a forage. We don’t want a big heap of poor quality stuff, otherwise you’re filling up space in the ration with poor quality forage. When forage is analysing similar to bought-in feed, it’s got a lot more value.”

The Bayleys run 565 cows across 290 hectares (720 acres) at Lady Leys Farm, Lullington, Derbyshire. The herd is milked three times a day and yields 10,800 litres at 3.9% fat and 3.3% protein.

In the past, silage ground was cut three-four times a year, although the fourth cut was viewed as a ‘bonus’, rather than a must. Now the farm plans to take five to six cuts a year, every five weeks, on a multi-cut system. The silagemaking season also starts earlier, with first cut taken in the first week of May or end of April, weather-permitting.

Due to the fact grass is cut younger and leafier, silage quality has improved markedly (see table). Now, it is possible for all cuts to achieve 11ME or more and 15-16% crude protein. However, Mr Bayley is keen to highlight this is only possible when the weather is in your favour, and the nature
of farming means every year is different.

He adds: “Our first cut is not any better now, but it’s the subsequent cuts that have improved in quality. The aim is to make all of our cuts similar to our old first cut.”

Digestibility

The high silage digestibility means cows are able to eat more of it, with Mr Bayley notably surprised at how much forage cows will eat. In 2017, the herd achieved forage dry matter intakes of 15kg DM per head per day. This enabled forage replacers, like moist feed, to be knocked out of the diet.

However, this year forage intakes are back at pre-multicut levels due to depressed forage stocks following last year’s drought. This meant only four cuts could be taken. This highlights the need to cut good quantities of silage in order to meet increased forage dry matter intake demands.

Mr Bayley believes by cutting five lighter cuts, he is producing the same tonnage as he was on the three-cut system, but energy and protein is better.

Having lighter cuts means it is important to pay attention to wilt times. He explains: “You can get through the acreage quickly as there is less of it [yields]. But you need to spread it immediately after cutting so there’s a rapid wilt.”

He aims for a maximum wilt time of 24 hours to achieve 35% dry matter. Mr Bayley also believes using the proven additive MTD/1 is essential to make silage ‘that bit better’.

Multi-cut – key considerations

ONE: Fertiliser

Reduced cutting interval means special attention needs to be paid to crop nutrition to ensure all nitrogen is absorbed before harvesting. This will prevent effluent issues in the clamp.

• Apply slurry into the soil immediately fields are cleared.
• Apply bagged fertiliser as recommended by an agronomist but not more than two units/acre for each growing day between cuts.
  
  

TWO: Dry matter

As with traditional silage-making, the aim is to wilt rapidly to achieve 28-32% dry matter. Be aware that this can be achieved much quicker on a multi-cut system as the crop is lighter.

Some farmers, particularly Dutch producers who commonly adopt multi-cut, take the crop a lot drier to about 40%. However, to do this, clamps need to be narrow enough to move across the face quickly to help reduce aerobic losses. Mr Ward advises going as high as is practically possible.

THREE: Chop length

As grass is young and leafy, fibre levels are lower. With a short chop, this can cause slippage in the clamp. At 28-32% DM, Mr Ward advises a chop length of 5cm versus 2-3cm on traditional systems. Clamps should also be filled in thin layers of up to six inches each to prevent slippage.

FOUR: Additives

As crops are younger, sugar levels are naturally lower. These sugars are essential to achieve a good fermentation. To ensure the sugars which are present are used for a healthy fermentation, rather than ‘feeding’ bad bacteria, a proven additive can help.

“We have found in younger, leafier silages, if we don’t put additives on, we don’t get the correct fermentation,” explains Mr Ward.

An additive also helps preserve the high protein levels in the crop and prevent them from being broken down in to ammonia.

Treating silage with MTD/1 (the beneficial bacterial strain in Ecosyl) additive has been found to increase the level of ‘true protein’’ in the silage by 31%, compared to untreated silage. This true protein is what is used most efficiently by the animal for meat and milk production.

Mr Ward also advises choosing a proven additive that can be applied at low volume (20ml/t versus 2 litres/t). As multi-cut is cut faster, with a shorter window, a lower volume helps efficiencies in the field.

FIVE: Ration balance

Fibre levels are a lot lower on multi-cut silage, while quality is higher. This means additional fibre will need to be added to the diet to ensure the cow is able to utilise the forage effectively. Straw or long-chop haylage could be considered.