Research proves multi-species swards improve production and performance

EARLY results from farm-based trials show diverse swards containing climate-smart species such as clovers bring production and performance benefits, with financial advantages too.

Leading plant breeder Germinal, through its research and innovation division Germinal Horizon, is investigating multi-species swards on the company’s research farm in southern England. Germinal is also supporting researchers undertaking grazing trials at University College Dublin (UCD). In contrast to the commonly seen ‘just give it a go’ approach to diverse swards, the team has applied scientific methodology so farmers can consider multi-species mixtures with more certainty.

Germinal’s plant scientists studied sward performance by testing six multi-species mixtures, ranging from classic perennial ryegrass to a 16 species mixture, comprising grasses, herbs and legumes. Yield, dry matter (DM), metabolic energy (ME), protein and overall seasonal performance were reviewed over two years.

The researchers at UCD monitored the performance of sheep and dairy beef steers grazing swards differing in species diversity, assessing liveweight gain, finishing time and frequency of drench applications.

When compared with perennial ryegrass, researchers found multi-species swards:

n Reduced nitrogen application by 60 per cent;

n Increased grass production by 12 per cent;

n Increased animal performance by 20 per cent;

n Accelerated slaughter by at least one month; and

n Reduced anthelmintic inputs by 50 per cent.

Overall production was good in all trial plots across the season. Perennial ryegrass alone yielded 14.8tDM/ha and the more diverse swards over 19tDM/ha.

Spring establishment was more successful than in the autumn, favouring the herbal elements needing warmer temperatures to germinate and grow. The primary legumes, red and white clover, proliferated over time and were more persistent than the herbs, contributing to the quality of the sward, along with the perennial ryegrass.

The role of clovers in fixing nitrogen and reducing the need for fertiliser was also confirmed. A detrimental effect was seen from higher fertiliser use on the diverse swards later in the season when the clovers were flourishing. This demonstrates it isn’t required in such quantity when clover is present and inhibits the plant’s nitrogen-fixing ability.

Germinal’s technical development manager Dr Mary McEvoy explains: “These results indicate how species interact and what each one brings to overall sward success. Our work in this area is creating a blueprint for farmers on establishment, grazing and management of multi-species. We’re committed to driving forward innovation, focusing on productive, profitable and climate-smart forage solutions at a time when farmers are facing a number of challenges.”

Reviewing the effects of multi-species swards on animal performance, Professor Tommy Boland from UCD says: “It’s exciting to be able to say confidently that offering animals swards consisting of more than a single species improves their performance. It isn’t a ‘silver bullet’ for all the challenges on farm, but I’m confident in saying multi-species swards form part of a farmer’s toolbox for the future.”