Herds' must have access to the optimum grass volume (kgDM/ha) during the grazing-period. But how do we measure this and what tools can be used? What covers are optimum versus area allocated? The ‘grazing platform’ should be measured with a pasture meter every week. The grass covers and quality needs to be recorded so a weekly budget can be determined for the next seven days.

The cover you need to aim for depends on various variable and local factors. These include the grazing strategy that’s being used, but also soil type and grass varieties. The most successful grassland managers with Lely Astronaut robots in Ireland, for example, aim for the following.

Covers to aim for

Between 1,100 and 1,400kgDM/ha (exclusive of 1,500kgDM/ha residual UK calculation)

- Post grazing cover at between 3cm and 4cm (more than 1,500kgDM/ ha residual UK calculation)

- It is important to consult with your local Lely Farm Management

Advisor in relation to current grass quality figures, as well as the exact requirements of your herd

Variation

- Towards the end of the grazing season, be aware of lower energy densities in the same area of allocation

- To compensate for the reduction in energy density of the grass, allocation of a larger area may be needed.

- To compensate for lower dry matter intakes due to wet weather a buffer feed, such as baled silage, can also be fed.

- Spring allocation dependent on availability and balanced with grass silage.

- Reseeded grass will have a different energy density even at the end of the grazing season.

- Different varieties of grass, as well as different diploid and tetraploid ratios, can also impact on available dry matter and energy.

- The grass later in the season will also have a different value, including increased protein levels, lower fiber and digestibility

Tips when measuring grass

- Accuracy is the key, take at least 50 random readings across the whole paddock

- Make sure to record these readings to build up a history of grass growth per paddock

Tip: This information than can be used to determine which paddocks require reseeding.

What size grazing area is required?

Dry matter intake will vary according to cow breed. But, as a general rule of thumb, maximum dry matter intake is approximately 4% of bodyweight. For example, the maximum dry matter intake for a 600-kg cow is approximately 24kg per day. Once the required cow intakes have been estimated and the total available kg of dry matter per hectare is known, it is a matter of dividing the herds dry matter requirement into what’s available in each paddock and then give them the required grazing access using temporary strip fencing.