Grassland strategies to increase animal feed efficiency

With sky-high input costs lately, the importance of high-quality grass has never been more in focus. With that in mind, here are three grassland strategies to increase animal feed efficiency.

1. Grass utilisation is the key to better efficiency

The profitability of Irish grass-based systems is not only dependent on how much grass is grown but how much grass is utilised. The amount of grass utilised is the grass that is consumed by the animal and used to produce milk and meat – this is the key driver of profitability.

Teagasc estimates that increasing the proportion of grazed grass in a dairy cow’s diet by 10% can lead to a 2.5c reduction in the cost of producing 1L of milk.

Furthermore, every additional 1t of DM utilised per hectare can increase profitability by €181/ha and reduce GHG emissions intensity by 4%.

Grass utilisation on farms is quite variable, with utilisation figures ranging from 5-12t DM/ha across production systems nationwide. Practical experience shows that certain perennial ryegrass varieties are easier to graze than others and this has been demonstrated in research trials at Teagasc too.

Thus, variety and mixture selection when reseeding have a considerable effect on how much grass is utilised on farm.

The importance of grass utilisation and the variability between varieties has been acknowledged by introducing the Grazing Utilisation Trait to the Pasture Profit Index.

This new trait gives a star rating to each variety that indicates how well a variety will be grazed. The ratings range from 1 – 5 stars with 5-star varieties grazed very well with greater rates of utilisation, and 1-star varieties grazed poorly.

DLF 4N Grazer Grass Mixture (intensive grazing mixture):

  • Mixture based on DLF’s NxGen Tetraploids;
  • Xenon and Nashota, in particular, carry the density of diploids;
  • Xenon and Aspect are the top two varieties in Teagasc grazing trials;
  • All varieties are late heading for extended sward quality.

2. Increasing clover content is a no-brainer

The use of white clover in grass mixtures has the potential to offset up to 150kg nitrogen (N)/ha/year in inorganic N fertiliser. With fertiliser prices increasing all the time, the incorporation of white clover into grass swards has the potential to greatly reduce the reliance on inorganic N fertiliser and increase the financial and environmental sustainability of Irish farms.

White clover is the most commonly sown legume in Ireland and is primarily used for grazing in mixtures with grass. As a forage, white clover is highly digestible with crude protein content averaging over 20%.

But the most significant benefit of white clover is its ability to fix N from the atmosphere for use by neighbouring grasses in the sward.

For maximum benefit a sward white clover content of 20-30% is required.

Benefits of white clover in the sward @ 20-30%:

  • +800kg DM/ha;
  • Opportunity to reduce N fertiliser;
  • Dry matter intake +1.5kg/cow/day;
  • Milk solids +30kg MS/cow/year;

Establishing and managing white clover in the sward

Establishing white clover takes time and some specific management. DLF recommends targeting up to 30% of the farm at a time in which to establish white clover.

Achieving good white clover content across the farm should be a medium-term goal and should be carried out over a number of years.

A full reseed is the most reliable method of establishing white clover. However, as the options for post-emergence treatment become more limited, many farmers are choosing to over-sow white clover into existing swards.

No matter what sowing method used the four key principles of successful establishment and management of white clover should always be considered:

1. Soil

  • Ensure adequate soil P, K and pH status;
  • Sow seed no more than 1cm deep;
  • Roll to ensure soil-seed contac.

2. Timing

  • Sow when the osil is warm (+10°C), and there is some moisture – ideally April to May;

3. Seed

  • Over-sow at a rate of 2-2.5kg/ac;
  • Use small and medium-leaf varieties for grazing and large-leaf for cutting.

4. Light

  • Over-sow after a tight grazing or silage cut so light can stimulate seedling growth;
  • After sowing, graze a 1,100kg DM/ha for the following three rotations to establish adequate white clover content.

Grazing management of clover

White clover should be managed with the aim of maintaining a sward clover content of 20-30%. This can be achieved by a combination of reducing inorganic N application and good grazing management.

When grazing grass-white clover swards it is important to graze covers of no more than 1,600kg DM/ha down to 4cm residuals. This prevents the grass outcompeting the white clover and allows sufficient light down to the clover stolon’s at ground level.

An early spring grazing will allow light into the sward to stimulate growth while leaving high clover swards for grazing last in the final autumn rotation will reduce the risk of winter grass growth smothering the white clover.

It is important to reduce inorganic N application on grass-white clover swards during the summer when white clover is most active and fixing N from the atmosphere. Where white clover content is above 20% in the sward, it is advised to reduce N application by half from May to encourage clover growth and maximise the amount of free N fixed by the plants.

Choose DLF N Saver Silage which is full of clover to reduce your requirements for N fertiliser.

3. Include multi-species in your reseeding plan

Incorporating multi-species swards into your grazing platform

Many farmers are using multi-species swards as a tool to greatly reduce their N fertiliser bill. This is very effective as apart from a couple of small fertiliser applications in spring, multi-species swards are almost totally N self-sufficient. In addition, as feed for grazing livestock, multi-species swards produce large quantities of highly digestible forage rich in minerals and high in protein.

Since the peak growth rates of multi-species swards occur in summer, they complement grass swards on the grazing platform perfectly. Having a mixture of grass and multi-species swards on the grazing platform will ensure a steady supply of the highest quality forage through spring, summer, and autumn as well as buffering against drought and reducing the cost of forage production.

Multi-species swards are a sustainable source of high-quality forage. As well as producing

high yields of quality forage, sowing a multi-species can lead to significantly reduced N fertiliser requirement, increased animal performance and health.

The benefits of multi-species swards

  • Multi-species swards can produce similar DM yields to perennial ryegrass swards at significantly lower rates of inorganic N fertiliser
  • Multi-species swards are a source of highly digestible, high protein forage and can maintain their high quality throughout the growing season.
  • The inclusion of warm-season species like chicory and red clover means multi-species swards have strong summer production compared to a grass sward.
  • These deep-rooting species make the sward much more tolerant of drought than a grass sward.
  • The inclusion of mineral-rich herbs provides a more balanced diet than grass alone, with species like chicory also providing some anthelminthic benefits to grazing livestock
  • The use of multi-species swards compared to grass-only swards in agriculture can also provide a wide range of environmental benefits including:
  • Reduced N2O emissions and nitrate leaching associated with reduced fertiliser use
  • Higher rates of carbon sequestration due to deeper root-depths
  • Enhanced biodiversity, particularly pollinators feeding on the variety of flowering plants in multi-species swards.

Choosing the right multi-species mixture for your farm

Multi-species swards are often thought only suitable for good quality, dry land. However, by selecting species that can better cope with wet or dry conditions, we can formulate different mixtures to suit different soil types.

For advice on multi-species swards, visit this agronomy guide

A good starting point is a mixture of species that will perform on a range of soil types like perennial ryegrass, white clover, and ribwort plantain. Once we have this foundation, the mixture can be tailored towards dry or wet soils.

In particularly light, dry soils, adding species like Festulolium, cocksfoot, lucerne and chicory will help keep the sward productive during prolonged dry periods.

On the other hand, in heavy, wet soils, species like timothy, meadow fescue and plantain are well equipped to cope with such challenging conditions.

A mixture like DLF’s 6 Species Herbal Ley is an excellent all-round mixture that should produce large amounts of quality forage across a range of soil types.

DLF Seeds

DLF has started its own on-farm variety grazing trial with four of their Grass Partners around the country.

In this trial, Dr. Thomas Maloney, DLF is examining the grazing performance of 21 different varieties to bring the best grazing varieties to the market. DLF is already seeing encouraging results from new varieties in seasonal and annual yield production as well as their grazing efficiency.

A notable trend to date is that, on average, tetraploid varieties are achieving much lower post-grazing residuals than diploid varieties. This suggests that including a higher proportion of tetraploid varieties in grazing mixtures should lead to better grazing efficiency and greater grass utilisation on farm.

On the back of DLF research and with the PPI grazing utilisation star-ratings, DLF have created the unique DLF 4N Grazer, an all-tetraploid mixture designed to maximise grass utilisation on Irish farms.

4N Grazer combines two 5-star grazing varieties, Xenon, and Aspect, with Nashota for a mixture that will hit all your grazing targets and provide quality forage throughout the season ensuring maximum grass utilisation.

For more information on selecting the right mixture for your farm to increase grazing utilisation, call Thomas Moloney, DLF 087 396 1265.