Leaving Certificate Agricultural Science

1. Leaving Certificate Agricultural Science Grassland – Part 4 Grassland Management

2. Grassland Management • Good Grassland Management involves the following: • Finding out the amount of herbage required. • The application of ample fertiliser to achieve this. • Maximising the DMD of the sward by managing grazing and conservation. • The amount of herbage output required is calculated by the amount / type of stock on the farm. • Generally 1 livestock unit consumes 12 tonnes of herbage dry matter per year.

3. Fertiliser Requirements • The amount of fertiliser applied to grassland greatly depends on the grazing level and the level of establishment. • Fertiliser should be applied to newly established grassland where grazing is light, in the following proportions: • N – 48 kg / ha • P – 20 kg / ha • K – 38 kg / ha • Intensely grazed pastures should receive additional fertiliser as outlined by Teagasc.

4. Fertilizer Requirements • Land set aside for silage or hay should also be fertilised in advance of each harvest. • Hay is only cut once over the grazing season while silage can be cut repeatedly. • The following is recommended by Teagasc:

6. Managing Grazing • Good grazing management requires young leafy digestible grass to be available for grazing at all times. • An efficient system of rotational grazing allows the farmers achieve this. • There are various systems available including Paddock Grazing, Strip Grazing, Block Grazing, Set Stocking, Creep Feeding and Mixed Grazing.

7. Grazing Management - 2 Paddock Grazing • Paddock grazing is the most efficient form of rotational grazing, whereby 20 – 25 paddocks are created using electric fencing. • The paddocks are created to suit the herd, using the rule: 120 cows will graze 1 ha of young leafy grass in one day. • The herd graze one paddock per day in a rotational manner. • Nitrogen is applied to the paddocks as soon as they are removed.

8. Grazing Management - 3 • By the time they return to the paddock, the grass should be at the height of its digestibility. • This system can be quite expensive but is widely used on dairy farms. • Silage fields are usually kept independent of the paddock system, as the small areas may be difficult to cut. • Calves & replacement heifers graze any replacement grass. • Paddock grazing systems are sometime called rotational grazing systems

10. Grazing Management - 4 Strip Grazing • This system involves the use of a movable electric fence, to give the stock a fresh strip of leafy grass per day. • Grass strips are fertilised in the same way as the paddock system. • A back fence should be used however, as to allow the grass recover sufficiently. • This system is cheap, but requires a lot of labour time and is therefore rarely used by itself.

12. Grazing Management - 5 Set Stocking • This is simplest, cheapest but least effective form of grazing management. • It simply involves allowing the stock free access to all areas throughout the grazing year. • This allows set – stocked areas to become patchy, with areas of highly un-productive grasses evident.

14. Grazing Management - 6 • Set stocking has a number of particular advantages. • Fencing and water troughs can be kept to a minimum and the continuous general nature of the grazing encourages a close dense sward that is usually rich in clover. • Set stocking is often practices in a modified way with beef, dairy and sheep systems utilising a few large blocks of pasture on a farm ( Block Grazing).

15. Grazing Management - 7 Block Grazing • This system is the most common system used in Ireland, as it is cheap, effective and low on labour. • It involves the division of the grazing area into blocks that provide grazing for 7-8 days. • Pasture management can be improved by using strip grazing in each block. • Larger blocks can be set aside for silage once or twice a year. • This system is cheap and is suitable for dairy, beef and sheep grazing.

17. Creep Feeding • This system involves allowing young animals access to the best grass by means of a fence with a hole only large enough for a calf or lamb. • The calf or lamb can “creep” through the small opening to the good grass but the adult cannot. • This allows the young animals to get the best grass, avoid worm infection and still allows the animals to suckle their mother.

19. Leader - Follower • This basically involves allow the younger animals onto a paddock, strip or block before the adults. • This again allows the younger animals to get the best grass and avoid picking up intestinal diseases. • It involves less “set up” than creep feeding. • It is common practice on dairy farms, when replacement heifers lead the main herd.