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Milk production

Managing grass for successful autumn grazing

Aidan Cushnahan, Greenmount Campus and Conor Maguire, Agriculture Development Adviser, Enniskillen Campus.
Dairy farmers throughout Northern Ireland in co-operation with Greenmount staff and Agriculture Development Advisers have demonstrated the opportunity to increase profitability through growing and utilising grass in the autumn. Grass for successful autumn grazing can be produced by slowing the speed of rotation, through the introduction of silage regrowths, strategic use of fertilizer and the removal of dry stock.
Autumn grazing management discussion
From left: Conor Maguire, Raymond Beggs, Aidan Cushnahan disccuus the production of late autumn grass.
This article examines the benefits obtained with autumn grazing and the management skills required plus the experiences of one Co. Fermanagh farmer (Raymond Beggs, Newtownbutler).

Why graze autumn grass ?

Local research and systems development work at Greenmount have shown that there are a number of significant benefits with extending the grazing season into November:
  1. Savings in silage - research has shown that 2 - 3 hours access to grazed grass can reduce silage requirements by 25 percent. In practice, at farm level, Raymond has seen these savings and when combined with an earlier spring turnout now budgets on an annual silage requirement of 7.5 tonnes per cow.
  2. Reduced concentrate costs - grazing good quality autumn grass is worth almost 2 KG concentrates per cow per day.
  3. Increased protein - the inclusion of autumn grass in the diet has been shown to improve milk protein content. Raymond has found this particularly useful in minimising the traditional drop in protein experienced at housing.
  4. A shorter housing period means less stress on cows, improved herd health and reduces slurry production all of which creates further cost savings.
The increased use of autumn grass over a number of years has helped contribute to increased profit on Raymond Beggs’ farm. Current performance is averaging 6,350 litres per cow, 4,540 litres of which is produced from forage with an average concentrate useage of 0.8 tonnes per cow.

Building the autumn grass supply

Producing grass for successful autumn grazing is a skill involving the management of grass during the late summer and autumn periods. It is important to make sure that pastures earmarked for grazing in October/ November are well grazed/ topped with no dead material. "My management policy at present is to graze or top pastures to a cover of 1,500 KG dry matter per hectare. This is essential if high quality grazing is to be maintained throughout the autumn period" says Raymond Beggs.
Supplies of grass are built up by gradually lengthening the grazing rotation and regularly monitoring the grass supply by walking the farm every week. This is carried out religiously on the Beggs' farm, with the added help of a plate meter. On most farms the average grass cover over the whole cow grazing area will gradually build up to around 3,000 KG dry matter per hectare by mid September.
Lengthening the rotation can be achieved by:

  1. Introducing silage regrowths


    The introduction of extra grazing paddocks by reducing the area used for third cut silage will increase rotation length. Aim to maximise the number of grazing days with these regrowths to allow grass yield to build up on the rest of the farm. Use of a back fence is essential to prevent regrowth being eaten or poaching in wet conditions.

  2. Fertilizer N


    Applications of 60 KG N/ ha (48 units/ acre) until early September will produce a satisfactory grass growth reponse. Applications of fertilizer beyond this date are not recommended from either an economic or environmental viewpoint.

  3. Destocking

    Removing dry cows and young stock from grazing areas suitable for milking cows allows a greater area to be brought into the rotation. However dry cows and in calf heifers can be used to clean out stemmy material prior to closing up for autumn grazing. Raymond has adopted this practice with his autumn calving dry cows.
Closing date of paddocks will have a big impact on the quality and quantity of grass available in autumn.

Start to accumulate grass on the driest fields of the farm from early September to allow grazing in November.

It is also important to remember that while increased access to grazed grass in autumn allows for savings in silage requirements, weather conditions may not always be suitable for grazing in late November. It is therefore important to have adequate stocks of silage as a contingency. Silage which is not used can always be kept for next year.

Summary

The financial benefits associated with producing more milk from autumn grass can make a very valuable contribution to dairy herd margins. Further details on how best to achieve this on your farm can be obtained from your local Agriculture Development Adviser.