 Grass is usually measured in kg of Dry Matter  Grass availability measured in kg DM/ha  Lowland ground has the potential to produce 12 tonnes DM per hectare per year

 However, due to lower inputs and poor grazing management typical utilisation in NI is 5.0 tonnes DM/ha  Well managed farms 8-10 tonnes DM/ha realistic target  Daily grass growth varies from 5kg DM/ha in February to 100kg DM/ha in May

 Includes what is left after grazing  Number of methods used 1. Sward assessment using rising plate meter 2. Visual assessment 3. Sward heights

 As rod is lowered into pasture, plate is supported by height and density of grass  This is averaged out over a paddock/field taking number of readings across field

 Walk each field in ‘W’  Take top leaf readings  Calculate field average and record  Keep record each week

1500 kgDM/ha 4-5 cm 2000 kgDM/ha 6-8 cm 2500 kgDM/ha 8-12 cm 3000 kgDM/ha >12 cm

StageCover kg DM/ha Sward height (cm) After weaningFat ewes Thin ewes Tupping18005 Mid-PregnancyGraze down to Lambing outside Move onto weeks pre- lambing 6

 Options 1. Apply nitrogen 2. Introduce supplementary feeding 3. Sell stock or cull unproductive animals

 Options 1. Increase stocking rate 2. Close up area for silage/Take area out for round bales 3. Reduce supplementary feeding 4. Reduce fertiliser rate

 Options 1. Pre-mowing or topping 2. Higher stocking rate 3. More measurement & management

 Grass growth varies throughout the season  Grow and graze leafy grass  Assess swards regularly  Take prompt action when surplus/deficit appears  Maximise utilisation

 Higher stocking rates and silage yields.  Higher grass growth response from fertiliser nitrogen.  Improved grass digestibility and palatability  Higher grass sugars and improved ensilability

ME (MJ/kg) Yield (t DM/ha) Perennial Ryegrass Yorkshire Fog Creeping Bent RSMG PRG has 20% higher ME content & 50% more yield

 The sheaths and backs of the leaves are smooth and shiny  Red stem base  Upper surface of leaf is strongly ribbed

 Walk a ‘W’ and assess at points how much PRG is in a sward.  If PRG below 70% - then some work to improve sward will be required  If PRG below 50% then reseed needs to be considered  If % of broadleaved weeds is high action will be required

1. Sward Replacement – destruction of old sward and replacement by reseed (plough or minimal cultivation) 2. Sward Renovation - introduction of seed into an existing sward with little or no cultivation 3. Sward Rejuvenation - gradual improvement to sward by better management.

 Required if % of PRG in sward is poor  Most reliable and conventional method of replacing a sward  Spring reseed is usually end March to mid May  Autumn reseed between mid July to late August  Spring reseeds often have a heavier weed burden than late summer reseed

 If high % of scutch/bent grasses or weeds like dock/thistles then old sward should be destroyed by Glyphosphate herbicide  Poor seedbed preparation is most common cause of failure  Seedbed to be fine and firm

 Consolidate without compacting  Sow 6-12mm deep  Roll to maintain moisture in top layer of soil  Watch out for pests (slugs, frit fly, leatherjackets)

 Alternative to conventional method of plough and reseed  Suitable for; 1. Stony soils 2. Heavy land that takes time to dry out 3. Where rapid establishment is required 4. Thin swards (silage ground)  Specialist drills/equipment required

 Control perennial weeds before over- seeding  Minimise competition from existing sward. Graze hard or cut silage immediately beforehand  Conditions need to be good (not too dry or wet)

 Graze lightly when grass seedlings are 10cm high. Graze often for short periods thereafter.  Do not allow long intervals between grazings or closing for silage

 Similar to over-seeding  Suited to Italian or hybrid silage swards that have thinned due to continuous cutting  Graze hard or cut for silage  Prepare a shallow tilth by discing and/or harrowing prior to broadcasting or drilling of seed

 Identification and correction of poor management practices  Reasons may include; 1. Poor drainage 2. Poor soil fertility 3. Weeds 4. Under-stocking 5. Poor integration of cutting and grazing 6. Poaching 7. Excessive use of slurry

Sward Replacement with ploughing Sward Replacement without ploughing Sward Renovation by stitching-in (Over-seeding) £/acre Soil analysis111 Spray23 Cultivations Seed & sow98 64 Fertiliser - sowing38 Lime – 2t + application 51 Total/acre

 Factors to be considered 1. Sward life – short, medium or long term 2. Sward purpose – Grazing or cutting 3. Growth season/area – early, intermediate, late 4. Soil type – dry & light or heavy & wet? 5. Always use recommended list varieties

 Use varieties with similar heading dates and dates which correspond with intended cutting date  Short term leys – use Italian ryegrass  Long term leys – perennial ryegrass  Clover inclusion of little benefit if intensive silage system (2-3 cuts)  Hybrids and tetraploids to be considered for high sugar content

 Persistence and ground cover are very important  Clover can have a role to play  Use mostly diploid varieties (more persistent)  Include some Timothy if ground is heavy

 Why include clover?  Improves digestibility and intakes  Increased animal performance  Higher protein % than grass  Increased mineral content of sward  Can reduce need to spread chemical N fertiliser

 Weeds cause economic loss in several ways; 1. They compete with grass for nutrients and light 2. Area taken up by weeds is not available for grazing 3. Silage made from weed-infested pasture will have lower palatability and energy 4. All lead to poorer than optimum animal performance

 Chickweed – annual, can be grazed out  Redshank – annual, common in spring reseeds  Ragwort – biennial, extremely poisonous  Thistles – perennial, topping not very effective  Dock – perennial, deep tap roots, keep spraying  Rush – perennial, common in poor, acidic, wet land, spraying very effective