Cutting grass in a multi-cut silage system has the potential to be more than £700 per ha more profitable than a traditional three-cut approach – even at milk prices nearer 40p per litre.

Furthermore, despite increased silage production costs, the financial benefit of multi-cut grass over three cuts has more than doubled in the last few years.

Those were the findings of new Volac analysis – using previous on-farm trial results that found that fresh-cut grass from a five-cut system had the capacity to support an additional 3506 litres/ha of milk from forage.

This was after five cuts were found to deliver 18,582 MJ/ha more metabolisable energy (ME) than three cuts, which, according to Volac silage scientist Dr Mark Leggett, was due to five cuts yielding more total dry matter (DM) over the season and having a higher average ME.

“Applying a milk price of 25p/l at the time of the trial (2019) to these extra 3506 litres/ha of milk showed multi-cut was £333/ha more profitable,” says Dr Leggett.

“This was after deducting £544/ha of extra costs for application of fertiliser and slurry, as well as contractor charges for cutting, raking, harvesting, carting and clamping the two additional cuts.

“Bringing this up to date by applying a higher, but still modest, milk price of 40p/l has revealed the financial advantage of multi-cut over three-cuts to have more than doubled – to £752/ha. Again, this was after deducting the additional outlay for the two extra cuts, this time of £650/ha to reflect cost increases.”

The significance of this latest analysis, is that with fertiliser and contracting costs having increased in recent years, and milk prices dropping back from the highs of 2022, farmers may be questioning the value of making multi-cut.

“Clearly, it’s not a system that suits all farms, but for this particular analysis, its extra benefit was clear.

“The other important finding was the multi-cut grass was also 2.8% higher in crude protein. Producing higher quality grass by cutting younger and more often with multi-cut may not allow producers to reduce the tonnage of concentrate purchased,” he said.

However, he added that it might mean a lower-cost concentrate, with lower ME and lower protein, can be fed. It might also mean less imported protein is used. Alternatively, higher quality grass can be used to help improve milk yield.

DM yield and quality results from the original trial were from fresh grass samples. Mr Leggett says the benefits of improved grass quality will not be seen unless the crop is preserved correctly, hence further research looked at multi-cut conservation – this time across four cuts.

“Compared with leaving grass untreated, the work found that treating with the additive Ecosyl – which applies a million Lactobacillus plantarum MTD/1 bacteria per gram of forage – reduced DM losses on all four cuts, and on two of the cuts by more than half. The results also pointed to better protein preservation by using the additive, and the number of enterobacteria – the undesirable bacteria associated with slurry – in the treated silage was up to 100,000 times lower.

“Using a proven additive to improve conservation of a multi-cut crop is an important consideration, since shorter intervals between cuts allows less time for slurry bacteria to decline. Also, the higher protein content of younger grass can contribute to buffering of the fermentation. The combination of high buffering and the action of slurry bacteria can lead to DM and nutrient losses. With farmers looking to improve milk from forage, it makes little sense to produce multi-cut as a way of improving forage quality if that quality is then lost during ensiling.”