Great rewards from good grassland management
First Milk Pioneer Farmer Grant Walker is using a rotational grazing system on his farm in Dumfriesshire. He tells us about its management and benefits he’s seeing.
We put cow tracks across the whole farm, which was essential to give us access to every paddock and allow us to continue grazing cows even in marginal weather. A new water system was also fitted.
Aiming for 24-hour paddocks, we have split up fields with single strand electric fencing. Multiple bungee gates and a well-planned track layout, gives us multiple entry and exit points. This is particularly important for early and late season grazing to minimise ground damage.
Through the main season, we aim to graze cows at 2800kg DM/ha with a residual of 1500-1550, although this is often easier said than done!
We find these levels give us the best balance between maximising cow intakes with palatable grass and growing high quantities. Moving into autumn we aim to increase the covers and the whole farm cover so the cows can stay out until late November. Regular grass measuring throughout the year is essential for grass budgeting.
In summer, cows are in a paddock for 24 hours, to achieve that balance of intake versus grass growth. Any longer and intakes vary too much with cows starting to eat the regrowth, reducing the amount of grass grown.
Stocking rates vary depending on grass supply and intake demand. We must understand how much the cows demand over the 24-hour period to determine the size of grazing area. Most of the summer cows are stocked at around 4 cows per hectare but this relies on good, consistent grass growth.
When we have surplus grass, we shut up paddocks for silage or take quick cuts for bales.
We aim to follow cows in early spring with a healthy application of slurry once a paddock is grazed. This is only achievable by leaving longer periods between grazing or we find grass rejection is high. We then try to apply nitrogen little and often once cows have grazed a paddock in main season.
We soil test the whole farm every three years and as this sampling has shown our slurry supplies all the P&K we require on farm, we usually spread just straight nitrogen.
We’re very aware calcium levels, and more specifically calcium: magnesium ratios, are important for soil function. Historically, the area has high magnesium soils, so we apply calcium as much as we can to improve the ratio.
Our soil testing includes organic matter levels. Using this, we target the lower organic matter soils with composted muck in the autumn to improve moisture retention and overall soil function.
We also include a good level of white clover in our grass leys which we find benefits the soil as well as increasing intakes. This year, we are trialling red clovers imported from New Zealand and plantain in the grazing leys to help maintain grass growth in dry periods, improve soil health further and increase intakes.
In terms of productivity levels, we have used the rotational grazing system since we took on the farm so it’s hard to know how it compares with previously, but the farm is growing significantly more grass now and carrying more cows. We feed around 800 kg concentrate per cow annually and aiming for 4000l milk from forage (MFF).
One of our biggest challenges remains grazing cows in late spring when grass growth can be hugely variable from week to week. Balancing high and consistent grass growth to hit pre-grazing cover targets with maintaining quality is difficult but the rewards are great. We’re seeing high MFF and economic production along with benefits to the soil and cow health.
When we start grazing in early spring, it always reminds us what a high value feed product grass is for milk production.
Read here to find out more about getting started with rotational grazing.