Multi-cut grass delivers higher profits from milk

• Benefits outweigh additional cost

• Not suitable for all farm systems

• Can mean less imported protein

A multi-cut silage system can deliver £700/ha more profit than a traditional three-cut approach – even when farmgate milk prices are at 40p/litre, says a study.

Despite higher silage production costs, the financial benefit of multi-cut grass over a traditional three cuts has more than doubled in the last few years, according to a new analysis by Volac.

The study used on-farm trial results which found that fresh-cut grass from a five-cut system had the capacity to support an additional 3,506 litres/ha of milk from forage – outweighing the additional cost.

Five cuts were found to deliver 18,582 MJ/ha more metabolisable energy (ME) than three cuts, says Volac silage scientist Mark Leggett. Five cuts yielded more total dry matter (DM) over the season with a higher average ME, he explains.

“Applying a milk price of 25p/l to these extra 3,506 litres/ha of milk when the trial was undertaken in 2019 showed that the multi-cut system 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.

With milk prices now about 40p/l, the financial advantage of a multi-cut system over the traditional three-cut approach has more than doubled to £752/ha – even though ag-inflation means an additional cost of £650/ha.

Dr Legett says the latest analysis shows that it can still be worthwhile making multi-cut silage even though fertiliser and contracting costs remain stubbornly high and milk prices have dropped back from the highs of 2022.

“Clearly, it’s not a system that suits all farms – but for this particular analysis, its extra benefit was clear,” says Dr Leggett. The original trial showed that the multi-cut grass was also 2.8% higher in crude protein, he adds.

“Producing higher quality grass by cutting younger and more often with multi-cut may not allow producers to reduce the tonnage of concentrate purchased.

Correct preservation

“However, 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 may be used to help improve milk yield.”

The DM yield and quality results from the original trial were from fresh grass samples. But the benefits of improved grass quality will not be seen unless the crop is preserved correctly.

To take account of this, further research looked at multi-cut conservation – this time across four cuts. It found that treating the grass with silage additive Ecosyl reduced losses on all four cuts compared with untreated grass.

Dr Leggett says: “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, says Dr Leggett.

“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.”