Rotational grazing – is it worth the hassle?

Maximising the proportion of grazed grass in the diet of each livestock system on-farm has been the cornerstone of the Farm Profit Programme. At a cost of less than 6p/kgDM, grazed grass is half the cost of grass silage and as little as a quarter of the cost of concentrate feed.

Growing more grass

The first step in this process is to grow more grass. This has been, and continues to be, improved by focusing on soil health and fertility. Around 20% of every farm has been sampled each year over the course of the programme and the farms have been working hard to correct their pH, phosphorus and potassium statuses.

Some of the farms are now completely GPS farm-mapped, to help monitor and maintain soil fertility.

Utilising the extra grass grown

Growing more grass is fine, but unless we can make best use of it by getting it into our grazing animals at the correct stage and maturity on a consistent basis,then growing the extra grass will have been a waste of effort and expense.

Rotational grazing

This is where rotational grazing plays a significant role in the overall system. It is the tool which allows the farmers to harness the greatest output (i.e. kg of grass dry matter) from every hectare on the farm.

Rotational grazing can sometimes be dismissed as a lot of work to set up and a complicated way of grazing livestock. However, it does not need to be. The most basic principle of rotational grazing is the idea of ‘graze and rest’.

Ideally, the grazing is done is short, intensive periods of no more than three days and the rest period is typically 15 to 18 days, depending on the time of year and grass growth rate. At this point, the grass plant is at its optimum for balancing both yield and grazing quality. Consistently grazing these swards will boost milk yield and increase liveweight gains in growing stock.

The Mackay Family Greenvale farm Dunnet, Thurso, Caithness

We have increased our stocking rate by 50% on the areas that we are rotational grazing. This alone has had a massive impact on the farm. It meant that last year, we could grow an extra 20ac of barley, as we freed up acres that would have previously been needed for grazing cattle.

As well as this, for the two years we have been using rotational grazing, we have weaned calves on average 14kg heavier than before the programme. Across the 94 spring cows that is an extra 1,316kg weaned from the herd each year. If we valued that liveweight at £2.35 that is an extra £3,092 of output just for moving the cattle every few days.

Last year, we also decided not to creep feed the calves until a fortnight prior to calving as the cows were milking so well and were in great condition. Typically, we would creep feed from early August onwards. Weaning heavier calves with less concentrate input was a real eye opener for us to the potential of grassland management.

Another bonus of rotational grazing is that the cattle quickly get used to being moved every few days. They are at the gate waiting to go when you open it. It has made the cows, and especially the calves, much more docile and easier to handle, as they are used to being moved all the time. We feel that we can now pick up any sickness in calves at an earlier stage, as we are in among them all the time and can see any changes earlier.

Andrew Gammie Drumforber, Laurencekirk

In the first year of the programme, we split up fields into five 5ac paddocks. Half of the ground was in new grass and the other half just in its second year. Rotational grazing has really helped tiller out and thicken the sward beneath the cattle’s feet.

We have been running as much as 40 cows on a 25ac block during the main grazing season. The biggest benefit for me is that I can get some extra silage from this ground in early summer. Grass growth can be slow to start here at Drumforber, but once it does take off, it can be hard to manage.

The last two years we have managed to take 10ac of the 25ac out at the same time as first-cut silage in late May. This boosts the silage reserves for the coming winter and also allows us to maintain the sward quality for the grazing cattle.

In the first year, we just put up temporary fences to make sure we were happy with the division sizes and fence locations. Once we were satisfied they were in the right place, we put up more permanent fencing and gates to ease stock movement around the block.

Water is one thing that you have to keep in mind, but the cost of an extra couple of drinking troughs is more than covered by the benefits of the system. In the lifetime of the project, we have increased from around 55 cows to over 90 to calve in 2020. However, we have only increased the amount of grassland by 17ac in this time – growing and utilising more grass per acre has allowed us to do this.

The Duguid Family North Cranna Aberchirder, Aberdeenshire

The first year of the programme, we split a 17ac field into four divisions for the ewes and lambs to graze. That worked well, but the following year we went to six paddocks per group, as we could see that the more paddocks we had in the rotation, the more control we had over the grass throughout the year.

Rotational grazing has had a huge impact on our sheep enterprise. We are now running eight ewes plus their lambs to the acre for the main grazing season. Every year, the ewes graze the new grass on the farm. This has two benefits, in that it is clean grazing for the lambs, so worm burdens are lower, and it also helps tiller out the sward in its first year.

We used to finish a lot of our lambs off turnips at this time of year. In the last two years, we have been drafting more and more lambs from grass earlier in the year. This year, we only had a handful of lambs on-farm at New Year.

The knock-on effects of having more lambs away earlier in the year means there is less pressure to have good grass for tupping the ewes. Therefore, they are going to the tup in better condition and this is starting to be reflected in the number of lambs we are weaning every year.

Another benefit of having lambs away earlier is that we can now winter more of the ewes on the turnips, whereas in previous years, they would have been on the grass parks throughout winter. The downside of this is that there was very little grass on the farm in early spring.

Since we are now resting more grass acres in the winter months, we have more grass when we need it in springtime, when ewes are lambing.

All these little changes can add up to make a huge difference when added together.