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Independent.ie

Tuesday 6 December 2016

Livestock farmers must make most of their best asset -- grass

John Shirley

Published 18/01/2012 | 06:00

Being of a mean disposition, I welcome this mild January weather. It allows me to switch off the central heating. The kind weather also brings an early stirring of the Irish livestock farmers' best asset -- grass.

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Now some may find grass a tedious or non-issue, but Limerick farmer John MacNamara offered a different perspective at last week's Irish Grassland Association (IGA) dairy conference.

"How I grow and use grass will determine mine and my family's standard of living," Mr MacNamara said.

Put simply, grazed grass offers a cheap and widely available source of feed. If you can find a consistent alternative, such as a feed by-product, then good for you. But for the vast majority, grass, with all its complexity, is the only show in town.

At the same conference (replicated in Athlone and Cork on Tuesday and Wednesday of last week to give national accessibility), Teagasc Moorepark's Michael O'Donovan outlined the latest in fine tuning to really have your grassland humming.

The table (right) outlines current reality and future targets based on measurements achieved on the best paddocks of top farms. That's a target output of more than 1,500kg of milk solids per hectare. Even at a modest milk price, this approaches €6,000.

Ironically, in the midst of the best practices of rotations, grass measurement, grass budgeting, reseeding etc, farmers are drifting away from what Mr O'Donovan calls the "foundation" for grass growing -- soil fertility.

"Reseeding is pointless unless fertility and pH problems are addressed, yet less than 50pc of dairy farmers are soil testing," Mr O'Donovan said. In practice, the Teagasc man claimed soil fertility levels are slipping.

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Other fine-tuning issues emerging from measurement on research and commercial farms and listed by the Moorepark scientist include:

• The huge variation in output between paddocks on the same farm. Reseeding the poorest paddocks is crucial.

• Grazing too tightly in early spring, ie below 3.5 cm, reduces overall output by 8pc, or 1.2 t/ha.

• Across the middle of the season, the optimum utilisation is when herds graze down to 4cm or 4.2cm.

• Grazing light covers of under 1,100 kg/DM/ha reduces overall grass yield by a whopping 40pc. Ideally, stock should enter a new paddock of grass at 1,400kg/DM/ha (a range of 1,200-1,600kg/DM/ha).

This strikes the balance between animal production and sward management efficiency. In old eyeballing terms, this should be leafy grass up to your ankles, or four to five inches.

• Spring poaching on dry soils hits the next grazing by 30pc but has little season long effect. Spring and autumn poaching on wetland can lead to zero immediate regrowth and a halving of season long output. The lesson to be learned is that on/off grazing is most critical on wet paddocks. Better still, drain them.

• The real benefit of ryegrass is in spring growth. A ryegrass dominant sward delivers an extra 2t/DM/ha by May, by which time the war is won. Even at a reseeding cost of €500/ha, Mr MacNamara reckons on getting the investment back in one year's grazing.

• New research in Moorepark is causing a rethink on clover and a belief that clover can still give a boost at high nitrogen (N) usage. At 180kg/ha of nitrogen, clover still boosts feed output by 2.5t/DM/ha.

The key is to use small or moderate leaf clover varieties probably with tetraploid grasses.

The next step in the grass story is the creation of an index for grass varieties similar to the EBI for cows. Teagasc, the Department of Agriculture's grass trial section and the ICBF are working towards this.

Close analysis of herd rotational grazing shows that the cow takes three bites at the same grass plant.

It's all about delivering maximum leaf all season long to the grazing animal.

Indo Farming