GETTING THE MEASURE OF GRASS

Working out the true feed value of grass can be difficult, but with a little attention to detail in this area farmers can significantly increase the proportion of feed grown on farm - reducing feed costs.

While compound feeds conveniently display all the required information on the label, grass is not quite so straightforward. But a few simple measurements can really improve productivity.

In almost all cases, the cheapest type of feed is grass grown on-farm,

So anything you can do to make more of the grass available to your livestock will bring dividends.

One of the easiest ways of managing grazing and grass yield is to use a swardstick to monitor grass height.

Unsurprisingly, the aim is to move stock into a fresh field once grass gets too short, but the swardstick makes the decision less subjective,

Some farmers adopt paddock grazing and use a rising plate meter or swardstick to measure grass. You graze a small area intensively for a day or two then move stock on. This is great for utilisation because the animals eat most of the grass.

The downside is that it is quite management intensive; you need to set up and move a lot of fences, plan and measure grazing very closely, and set up tracks for access. It does not suit all systems and approaches, for example, if you are grazing sheep or beef cattle, setting up and managing a rotational system can be a challenge.

But there are still ways to boost productivity, measuring sward height is beneficial in set-stocking, strip grazing and semi-rotational systems. By working to grazing height targets, you can increase grass utilisation by around 10-15% and promote more high quality grass growth later in the season.

When grass falls below target height, move stock on to new area, or tighten up the grazing area when height moves above target.

says CF Fertilisers Farm Adviser Hefin Llwyd.

Target heights for grazing from turn-out until May are given in the table below:

  Pre-graze (cm) Post-graze or target for set stocking (cm)
Ewes and lambs 08-Oct 04-Jun
Cows and calves Oct-14 05-Jun

(adapted from EBLEX BRP Manual 8)

To use a swardstick, you need to take 20 to 40 random height measurements of the undisturbed grass leaves from across the field.  These should include the height of rejected patches around dung pats, but avoid seed heads, stems, weeds, gateways, drinking troughs, field margins and areas under trees.

Do this regularly in the spring to track the direction of grazed grass height. Once you have worked out the average height you can decide what to do next.

Taking measurements and recording them will help with long-term planning too:

It's very important that pastures recover before being grazed again, so regular applications of fertiliser with a balance of all nutrients is important, keeping track of pasture growth will tell you if the applications are right.

You can also identify any land which is poorly performing and take steps to rectify this such as reseeding or improving soil structure.

For the more technically-focused farmer, the swardstick measurement will also enable calculations on the amounts of dry matter in the grass, as well as the height.

It may seem a daunting prospect but once you get into the habit of taking measurements some people might fancy giving it a go,"

enthuses Hefin.

CF Fertilisers is currently distributing a limited number of free swardsticks. To get hold of one, speak to your local CF Fertilisers farm adviser or call 0151 357 5758.