Grasstec: Grazing plan will reap spring awards

COMMENT:  An autumn rotation planner and corresponding autumn budget a must.

The week just past continues to record above average grass growth rates as soil temperatures remain high. On average growth is 50-55 kgDM/ha in the South and East and 5-10 units lower in the North and West.

UK figures are similar with growths up to 70 recorded. – either way these figures are 20-25 per cent above those expected for the time of year and very much welcomed. Many who were drought stricken two weeks ago have increased cover significantly as a result of good management (lowering demand) and weather conditions – example in the graph below(UK example showing total cover).

High pressure to our west is yielding blue sky by day but cold nights follow – this is the main thing to lower soil temperatures and so a drop in growth will be expected over the coming weeks.

This means that nearly all farms are now past Autumn balance date, where demand will exceed growth from now on. Consequently, farm cover is likely to drop from now on until the end of grazing in November. You need to continue to measure weekly to ensure that this drop in cover is controlled – adjusting the demand according to grass supply.

The most common question when advising farms this week is “What cover should I finish grazing at”?, the answer to which is unique to each farm, but is a function of Spring stocking rate, calving pattern and expected Winter growth.

This can only be answered by doing a Spring budget, which takes cognisance of the calving pattern and associated demand compared against the expected growth– by working back from April magic day we can predict what the opening cover needs to be. Taking Winter growth into account we then know what the closing cover needs to be. A long winded answer to the question above but easily done with the help of the grass software programmes out there such as  Agrinet and Kingswood.

Nearly all farms have scanned their herds at this stage, and so you are armed with this calving pattern information. If you have a much improved early calving pattern compared to previous years then it is essential that you calculate the target opening cover in Spring and then you know the closing cover.

Another essential grassland management tool at this time of year is the Autumn rotation planner which is easy to create and easy to follow. One simple rule applies “to graze 60-65 per cent of the farm in the first 30 days of closing”.

This helps to guarantee that enough or area is grazed off in early Autumn that is re-growing long enough through late Autumn and Winter to have plenty of grass available for grazing in Spring. The “start of closing” depends on the location and growing ability of the farm. Late growing farms on colder heavier soils should start closing their paddocks grazed after 2-3 October whereas lighter warmer soils should start closing paddocks grazed after 10-12 October. Lets do an example – consider a 100ha farm in the midlands, frost prone and on medium to heavy soils.

  • Start for closing – 2 October
  • Target % of land to be grazed/closed 30 days later (1 Nov) – 65 per cent
  • 100ha x 65 per cent = 65ha to be grazed by 1 Nov.
  • 65ha/30 days = 2.16ha/day to be grazed.

In the example above the remaining 35 per cent of the area should be grazed between 2 November and the planned end of grazing preferably in late November ground conditions permitting.

In the majority of cases, if grass supply is high, the expected grass intake as per your Autumn budget will correspond with the Autumn planner and vise versa. Projecting forward through October and early November, if grass growth drops significantly and cover decline is too fast then the stick to the Autumn planner religiously and supplement accordingly.

If you have not yet updated your Autumn budget or completed an Autumn rotation planner, please set aside time over the next few days to do so. Your decisions and management over the coming weeks has an effect on grass supply for the next 6 months. Remember, Spring grass is worth approx €2.70 per cow per day, whereas late Autumn grass is worth approx €1.50 per cow per day.

Agriland 111013 budget

By Noel Gowen, consultant with Grasstec Dairy Solutions who provide a dairy consultancy, farm infrastructure design and livestock sourcing service in Ireland and UK.  Noel can be contacted on +353 (0)86 8360285 or [email protected]

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