Cut to Clamp Series: How a multi-cut silage system can result in better-quality forage

In the third and final part of the ‘Cut to Clamp Series’ – brought to you by AgriLand and Volac – Volac’s silage scientist Philip Jones looks at new research showing how taking five cuts of silage in a season, rather than three, could improve the energy content of the grass.

Maximising the energy in your grass and ‘locking-in’ as much of this as possible into silage is vital. A key foundation for milk production is the amount of metabolisable energy (ME) available to the cow, says Philip.

Indeed, it takes about 5.3 megajoules of ME for a cow to produce 1L of milk. To insulate your business against volatile feed prices, providing as much of this ME as possible from home-produced forage and silage is a ‘no brainer’, he adds.

“Here in Ireland, we can grow good grass so let’s make the most of this natural asset. An interesting way to view this is the amount of ME you can make available from your grass/ha.

Volac silage scientist Philip Jones

“We know that new leys are more productive than old ones. But in addition to growing nutritious grass, with silage generally fed for half the year, it is also important to ‘lock-in’ as much of this nutritional value as possible when turning it into silage.”

The six stages involved in making top-quality silage:

Cutting;
Wilting;
Harvesting;
Treating;
Clamping;
Feeding.

However, two particular steps attracting increased interest for improving silage are cutting grass at the optimum growth stage and including a proven additive as an integral part of the conservation.

If cutting is delayed until after heading, the digestibility of grass – which determines its ME – falls by 0.5%/day.

Similarly, animal feeding trials have shown that conserving silage with Ecosyl additive has significantly improved ME – from 10.6 MJ/kg DM to 11.2 MJ/kg DM.

Indeed, further research found that feeding silage preserved with Ecosyl also led to cows producing an extra 1.2L of milk/cow/day.

New research

The latest Volac research has taken this a step further by focusing on the progressive technique of cutting grass younger and taking more cuts per season using a multi-cut system, as well as on conserving this potentially high-quality forage.

“Theoretically, we know that multi-cut silage should offer several nutritional advantages,” explained Philip. “As well as being higher in protein, younger grass should also be more digestible, and therefore naturally higher in ME.

“Accordingly, our latest Volac latest two-year research project, which was conducted in a real farm situation, examined these quality parameters.

“By measuring yield, we were then also able to derive a figure for how much extra ME/ha the multi-cut system could potentially deliver.”

Source: Volac two-year research project

Fresh grass from the five-cut, multi-cut system was clearly of higher nutritional quality than from the more conventional three-cut approach.

Average digestibility from the multi-cut was 3 D units higher, at 72.7 versus 69.7, which equated to it delivering an extra 0.5 MJ/kg of ME. In addition, crude protein content was also almost 3% higher, at 16.7% versus 13.9%.

“When overall yield was measured, we found that five cuts also delivered an extra 0.92 t/ha of DM in total, with a DM yield of 16.92 t/ha.

“Once this extra 0.92 t/ha of DM was multiplied by its higher energy content, this was equivalent to it providing an extra 18,582 MJ/ha of energy over the season.

“If you take 5.3 MJ of energy being required to produce 1L of milk, this means the multi-cut had the potential to deliver an additional 3,506 L/ha.”

As well as demonstrating the extra energy potential of the fresh multi-cut grass, the new research also shed light on improving its preservation.

Source: Volac two-year research project; second of four cuts as an example

While the higher protein content of multi-cut is a benefit, nutritionally, it can also contribute to buffering of the fermentation.

In addition, shorter intervals between cuts means less time for slurry to dissipate before the next cut is taken, which increases the risk of slurry bacteria in the silage. The combination of high buffering and the action of slurry bacteria can lead to DM losses.

With these challenges in mind, a further part of the research examined how these might be mitigated, by comparing how the fermentation proceeded in multi-cut samples without an additive, versus where Ecosyl was used.

Source: Volac two-year research project; second of four cuts as an example

Results showed that not only was the fermentation slow without the additive, with pH levels never reached those achieved in the treated silage even 90 days after ensiling, but there was also a big increase in enterobacteria numbers – the bad bacteria often associated with slurry, where no additive was used.

Ultimately, nearly 10% of the DM was lost across all cuts of the untreated silage and there was evidence of protein being broken down.

Source: Volac two-year research project; average of four cuts

Where Ecosyl was used, not only was the fermentation faster, with the pH falling rapidly, which is key to inhibiting bad bacteria – but enterobacteria numbers were between 100 and 100,000 times lower and the average DM loss was almost halved; there was also evidence of better preservation of protein.

Thus multi-cut grass offers the potential to ‘grow more milk’ by providing a higher output of ME/ha, but it does need conserving properly; treating with Ecosyl certainly helps to achieve that.

Ecosyl

Using Ecosyl as a silage additive results in better-quality silage. A lot of factors will influence animal performance with silage quality being an important one as it represents such a large proportion of the ration.

In order to capture as much of the nutritional value of the original forage, it is important the fermentation is fast and efficient. 200 trials over a wide range of crops and ensiling conditions have shown that using Ecosyl will improve both of these parameters.

Silage analysis is not a reliable indicator of animal performance as there are many other factors involved that are not determined.

So, the only way to prove an additive can improve animal performance is do full-scale feeding experiments and that is where Ecosyl stands head and shoulders above most other silage additives as there are now 33 independent animal trials behind it.

Ecosyl also adds better aerobic stability and reduces high DM losses; it also helps if harvesting takes place in poor weather conditions.

MTD/1 is the unique high performance strain of Lactobacillus plantarum in Ecosyl inoculants. It’s been thoroughly proven over a wide range of crops and ensiling conditions to improve fermentation and animal performance.