Spring Grazing Deficits: Why Isn’t the Grass Growing?

Across the UK, many farmers are reporting grazing deficits. This occurs when the demand for feed from pasture is greater than the amount of grass actually growing. When this happens, farmers must provide animals with extra feed to keep them healthy and maintain growth. With peak lambing season upon us, there are many extra mouths to feed in UK flocks. So why isn’t grass growing as much as expected? And what can you do as a farmer to help mitigate this?

When is peak grass growing season?

April and May are usually the best months for grass to grow. The weather is, usually, perfect for grass; damp and not too cold. Growth is measured in kilograms of dry matter, per hectare, per day. While the expected growth this year is around 38.1kg DM/h/d, we are only seeing growth rates of around 24.4kg DM/h/d, leaving a deficit of over 13kg that farmers are having to make up for with additional feed.

Around this time of year is also crucial for pretty much all livestock farmers. Sheep are having lambs, many dairy cows are reaching peak lactation, and beef calves are growing quickly. Making sure all animals have enough to eat is a priority. If grass stocks are low, this can lead to unexpected costs. These could be buying in extra hay, feed, or the need to open pastures intended for other use. Additionally, large amounts of land are not available to graze on, due to reseeding of winter forage areas.

Grass grows best when weather is damp and warm.
Grass grows best when weather is damp and warm.

So what is causing this lack of growth?

In short, it is both too cold and too dry for grass to grow properly. The Met Office has recorded low temperatures of -5.5°C in mid-April, and, although daytime temperatures are relatively warm, these frosts are keeping grass growth low. On top of that, it’s been a very dry April. Soil moisture is low and there is little rain forecast. April showers have been somewhat lacking this year.

These factors combine to prevent the fast grass growth we expect to see in spring. Walking through fields of hard and cracked ground, you can see that, although the grass is there, it is hardly thriving.

What can we do about it?

Although we can’t do much to change the weather, we can make plans to mitigate it effects. For all who rely on pastures, one of the most important things to do now is to measure and understand how much grass is growing and how much grass is needed. You can measure grass easily using a sward stick or a platemeter and then compare it against national rates.

The AHDB have a feed calculator which you can use to calculate how much feed your livestock will need. Alternatively, you can estimate feed demand based on previous years’ data. Generally speaking, milking cows need the most feed, while weaned lambs need the least.

Once you have an idea of how much grass is growing and how much feed your animals need, you can then prioritise grazing on pastures for the animals which need it most. If there isn’t enough grass, you can supplement with silage or other feed stocks, or rotate animals into other pasture.

Grass is not growing sufficiently, so animals that are out to pasture need to be given additional feed.
Grass is not growing sufficiently, so animals that are out to pasture need to be given additional feed.

What not to do

There is little point in using nitrogen or urea-based fertilisers on pasture land when rainfall is low. Both urea and nitrogen require water to be taken up by the plant. If you put these fertilisers on in dry conditions, much of it will be wasted. Revise any fertilisation plans until more rain is on the horizon, or fertilise only in small areas where water is present.

Be aware that moving flocks and herds more regularly between pastures can expose them to greater parasite loads. Now might be a good time to take a Pasture Larval Count Test and find out exactly what parasites you might be exposing your stock to.

It’s not all bad news!

Dry ground and less mud can help to keep down various infections in livestock. Diseases like footrot and foul-in-the-foot can be exacerbated by muddy ground. Both rumen fluke and liver fluke, common and economically damaging parasites, require the mud snail Galba truncatula for part of their lifecycle. As this snail thrives in wet and muddy conditions, dry spells can help to keep infections down. You should stay vigilant once rain begins to fall again, however, as the immature fluke can stay dormant for a long time and can easily reinfect a population.

Last year saw grass growing deficits around this time of year as well, so it is possible that this might become the norm. With that in mind, perhaps now is the best time to start implementing new strategies and management systems to keep animals healthy, even when grass growth is low.