By Poppy Frater, Scotland’s Rural College (SRUC)

The biggest benefit of rotational grazing is increased grass utilisation. Animals have less opportunity to waste grass and therefore more of the grass is converted into meat, milk, wool and lamb. This translates into greater stocking rate potential and/or greater hay or silage production. Rotational grazing is simply moving stock through a series of fields or paddocks on a regular basis (every one-14 days) to give the pasture a short burst of grazing pressure followed by a rest period.

The partners of the EU SheepNet project have written new factsheets that build upon the existing wealth of resources accrued across the seven countries. I wrote one of the latest additions: A Simple Approach to Rotational Grazing, with Roberto Ruiz, Neiker-Tecnalia, from the Basque Institute for Agricultural Research and Development.

The guide sets out a rotational grazing set-up example and provides some guidelines for stocking density and grass height targets.

Set-up

'Grow enough grass in three weeks to graze in three days’ is the premise of the three week-three day system. Pasture gets a three-week rest while animals are moved every three days. This 24-day rotation would involve eight paddocks of similar size.

In the spring, when grass growth is at its peak, one or two paddocks might be skipped to maintain grazing pressure and take a cut of hay or silage and the full rotation might be returned to in the summer.

Some guideline figures

Stock Maximum group size Guide stocking rate numbers/ha*(number/acre) Area for maximum group ha (acres) Paddock size for maximum group** ha (acres) Target grass height - Entry cm Target grass height - Exit cm

Growing cattle 100 4 (1.6) 25 (62) 3 (7.5) 10 5

Finishing cattle 80 3.5 (1.4) 23 (57) 2.8 (7) 10 5

Ewes and singles 350 13 (5.3) 27 (67) 3 (7.5) 8 4

Ewes and twins 250 11 (4.5) 23 (57) 2.8 (7) 8 5

Spring calving cows and calves 50 3 (1.2) 17 (42) 2 (5) 8 5

Autumn calving cows and calves 60 4 (1.6) 15 (37) 1.8 (4.5) 8 4

Dairy sheep*** 200 29 (11.6) 7 (17) 0.8 (2) 10 5

Note: * Across the whole rotation **based on the three week rest, three day graze, i.e. area divided by eight. ***based on the three week rest, one day graze, i.e. area divided by 24.

This table, taken from the Factsheet, sets out a guide for group sizes and stocking rate for different classes of stock. These are based on conservative summer grass growth assumptions (40kg DM/ha/day) which leaves flexibility to increase stocking when grass growth is higher in the spring.

The most important message is to use these figures as a starting point and adjust. A key indicator is grass height on entry – when too high, paddocks should be skipped. When too low, the rotation needs to be extended to give the pasture more rest.

The next step would involve quantifying grass as a feed – kgs of dry matter per hectare – using the Quality Meat Scotland sward stick, freely available from QMS. These can be used to monitor grass growth to understand whether stocking rate is appropriate.

Although the potential to increase stocking rate is there, we recommend increasing stocking density before increasing stocking rate. In other words, through rotational grazing, increase the daily stocking pressure to make more from the pasture and learn the system before you increase animal numbers across the farm. See the SheepNet knowledge reservoir for the