Grass and silage: Why should UK farmers consider using a zero grazing system?

Improvements

She says: “Studies have shown that maintaining covers slightly lower at about 3,500kg DM/ha increased grass quality, grass growth and usage compared to sward covers exceeding 4,500kg DM/ha.

“At these heights, cow intakes did increase and we saw improvements in milk production and quality compared to cows fed grass from high cover swards.”

Consideration and potential investment is needed ahead of implementing a zero grazing system, says Dr McConnell.

“Rough estimates suggest it would take about one hour to feed 100 cows on a zero grazing system, so labour requirements should be considered, although this is variable from farm to farm depending on infrastructure, distance the fields are from the farm and equipment.

“Zero grazing systems are also dealing with a more volatile product in comparison to a silage system for example, and this can be challenging, particularly for high yielding cows.”

She says some capital investment is likely to be needed longer term for specialist machinery, as well as the potential for higher costs around slurry storage and spreading. A greater indoor feed space is also needed.

Foodstuff for UK dairy herds – the numbers

6p/kg DM: The cost of grazed grass
10p/kg DM: The cost of grass silage
25p/kg DM: The cost of purchased concentrates

33 per cent or 9.5ppl: The total production accounted from feed and forage
1,000 litres: The increase in milk from forage figure which equates to a £10,798 net profit difference on a 100-head herd

Source: AHDB

IN THE FIELD: TOM KIMBER, WINCANTON, SOMERSET

TOM Kimber, Wincanton, Somerset, is a ‘convert’ to cut and carry and has been using it through the shoulders of the season since 2016, when the late spring prevented him from turning out his cows.

With the 220-strong Friesian herd split into a spring and autumn calving block, Mr Kimber says he relies on producing milk from summer grazing to achieve a 7,000-litre annual yield, at 4.4 per cent fat and 3.45 per cent protein.

The bad weather three years ago, coupled with depleted silage stocks and land close to the farm being too wet to support grazing, gave him no option but to turn to dryer fields some distance away for grass, which he cut and took back to the cows.

He replaced the fourth cut silage element of the total mixed ration (TMR) the cows were being fed at that point with grass and was impressed with effects after milk yields rose back to where they were before he started using the fourth cut.

The system that year continued until grazing could resume, by which time Mr Kimber was sold on the cut and carry concept.

Yields have increased by 1.5 to two litres per day in comparison to a TMR based on maize and fourth cut, with milk from forage on target to exceed 4,000 litres per year.

As the summer approaches, cows will go out by day and receive cut and carry during housing at night and eventually, during the summer, will graze full-time and only receive concentrates in the parlour. The system goes into reverse in autumn, with cows continuing to graze by day and given cut and carry at night.

Mr Kimber says: “After they are fully housed they will have one feed of TMR and one of cut and carry grass which will continue as the season allows, often to late October, before finally moving to the full TMR.”

Saving

Winter rations are based on a TMR of about 60 per cent maize, 40 per cent grass silage and 2.5kg of a 36 per cent protein blend, with one feed of TMR replaced by grass as soon as it can be cut, which Mr Kimber says is usually from March onwards. With higher levels of protein introduced through the fresh grass, a saving has also been made on the blend fed in the TMR.

“When the fresh grass comes into the ration, we switch from a 36 per cent crude protein blend to one containing 16 per cent protein, which saves us about £50/tonne,” he says.

Although some investment is needed for cut and carry, Mr Kimber explains that he used a neighbour’s adapted mower which would tow a trailer when he first started with it.

The borrowed machine has since been replaced by a second-hand zero grazing machine, which he bought for £7,500.

“It would be hard for us to justify a £50,000 investment in one of the more modern zero grazing machines,” he says.

“We can still get the parts for our old machine although there is nothing much to go wrong, so we will continue with this system for as long as we can.”

Tips for the shed

■ Allow enough space and regular push-ups needed to achieve optimal intakes
■ Feed rate – offer 110 per cent of herd requirement to factor in wastage
■ Regular testing to monitor quality
■ Deliver food every day to avoid heating and spoilage and remove wastage
■ Monitor dry matter intake so buffer feed can be fed if required

Tips for the field

■ Consider field size (not too large), previous use (avoid grazed land) and access (minimise soil compaction)
■ Increased nutrient requirement
■ Grass quality - pre-cutting covers target for cut and carry is between 3,500 and 4,000kg dry matter per hectare.
■ Time of day – peak DM content from midday to early afternoon