How to develop a rotational grazing plan for cows and calves

Get a farm map and divide into rotations, based on similar field sizes, location or accessibility. Previous grazing history is crucial at this stage, as it is likely the rotations will be based on what has happened before.

Work through an example based on the rotation below for a group of stock.

Example

• 35 suckler cows and calves are to be grazed on a rotation area of 12–30 ha
• There are up to 30 1-ha paddocks from March until October
• Silage is planned for some fields
• The group’s daily allocation is around 600 kg DM, based on the cow’s average weight of 680 kg, with an allocation of 2.5% of body weight for the cows and 3% for the calves

The calves will have little initial intake, but this will grow through the season. The rotation will change as the area available changes and the grass growth increases or decreases.

For the example, the first rotation will consist of 30 paddocks while the grass growth is lower at 25 kg of DM per ha during the spring. In this instance, the rotation is increased to 30 1-ha paddocks, with the cows spending two days in each paddock. Therefore, in total, the rotation would last 60 days.

Example rotations for cows and calves

As the cattle move into the second rotation, grass growth has increased dramatically to 70 kg DM/Ha. The cattle are unable to keep up with grass growth as demand per ha remains at 595 kg DM/ha, while grass growth amounts to 2,100 kg of DM/ha. To maintain entry covers of 3,000 kg DM/ha, 18 paddocks are shut out for silage. This helps maintain the pre-grazing target height and will help maintain the quality of grass in front of the cows through this period.

For the third rotation, cow demand has increased to 20 kg of DM, due to the increased demand from the calves as they grow. Coupled with this, dry matter growth has reduced to 45 kg of DM per ha. Therefore, the rotation is increased to 21 paddocks with the full rotation lasting about 36 days. This still leaves an unused area of 9 ha which could be used for other stock such as finishing cattle or a further cut of silage could be taken from the grazing platform.

You need to monitor pasture cover and stock performance to make sure the rotation is going as predicted and allocations are appropriate, as grass growth varies.

If pasture covers are not being met, look to slow down the rotation. It could be worth feeding supplementary feed to ensure the grass is recovering in front and behind the animals.