The Courier & Advertiser (Fife Edition)
Green role for grass seed
Grass and clover breeders out to increase animal production and address issues linked to climate change
Grass and clover breeders are making significant improvements to their varieties to boost farm output while easing environmental pressures created by intensive animal production.
Varieties of grass and clover tend to stay on the market for much longer than those in the arable sector – in some cases, decades – so innovation has historically been much slower. However, over the last 15 years, improvements have accelerated, particularly in terms of dry matter yield, energy content and ruminant digestibility of grasses used for grazing and conservation cuts.
In turn, this improvement is helping increase dairy and meat output, reduce waste and cut methane production from grazing animals – a major greenhouse gas contributing to climate change.
This has been driven, in part, by the Institute of Biological, Environmental and Rural Sciences (Ibers) facility at Aberystwyth University in North Wales, where perennial and hybrid ryegrasses with higher water soluble carbohydrate contents, or “high sugar” grasses, have been developed.
Just across the Irish Sea, the Agri Food & Biosciences Institute (AFBI) has also been running a grass breeding programme at Loughgall, Co Armagh, Northern Ireland for many years. This has been funded by the NI Department of Agriculture (Dard) and since 1991, Dutch grass seed company Barenbrug, which has exclusive marketing rights to AFBI varieties.
The programme has more recently focused on early spring growth, disease resistance and winter hardiness, plus similar considerable efforts to improve digestibility and select for grasses with lower re-heading in mid-season.
Grasses bred from either institute that have potential for the Scottish market are tested rigorously by Scotland’s Rural College (SRUC) in unique and varied growing conditions in Ayrshire, Edinburgh and Aberdeen.
The best candidates make it on to the recommended list as “first choice” varieties and SRUC’s grassland specialist David Lawson says it is vital farmers ensure their seed merchants are providing seed mixtures made up of these top options.
They will inevitably have a high D-value – which gives an indication of how much of the grass’s dry matter the animal can digest – and the best characteristics in terms of ground cover and resistance to pathogens such as crown rust and leaf spot.
“What typically happens is, a variety will make it on to the list and seed merchants will use it to make up the mixes, so they automatically improve their first choices. For farmers, they can look at the recommended list on the SRUC website and check what they are getting,” explains Dr Lawson.
Paul Billings, managing director at seed producer Germinal GB, which exclusively markets Ibers varieties, agrees that sticking to first choice options is essential to maximising production from grasses and differences between recommended varieties can be significant. “A 1% improvement in D-value equates to a 5% increase in animal performance and with a 4-5% variation in D-values across the list, that’s a 20-25% difference in total production. If you stick to the top recommended varieties, you won’t go far wrong,” said Mr Billings.
In addition to D-value improvements, breeders at Ibers are also researching the lipid composition of ryegrass, with a
If you stick to the top recommended varieties, you won’t go far wrong
view to using plant breeding to manipulate the oil content of future commercial varieties. At present, the oil content of perennial ryegrass is typically 2-4% but, according to Mr Billings, Ibers is seeking to double it to 6% and significantly improve the fat profile animals gain from grazing and potentially produce healthier products for human consumption.
“It will shift the profile from saturated fats to polyunsaturated fats and we would hope to see that passed on into the meat and dairy products produced from the grasses,” he adds.
In addition to production benefits, the modified fatty acid composition will also reduce methane production in livestock systems and help to address climate change concerns and contribute to a more sustainable farming system.
Nitrogen use efficiency in grass crops is also a concern, with fertiliser a huge cost and a big polluter, so improving utilisation of the macronutrient will give the industry a production and environmental win-win.