SPECIAL REPORT
RYEGRASS
Lipids: Catching them in the rye
R
Words by: Anne Lee yegrass may have a role to play in the future in curbing methane and greenhouse gas (GHG) emissions and in creating greater tolerance to a changing climate. Germinal New Zealand general manager Sarah Gard says ryegrass underpins our whole pastoral system and as the climate changes and farmers’ needs change our pastures will have to adapt too. But that doesn’t mean ryegrass will be on the outer - on the contrary it could hold some of the solutions. Breeding for ryegrass with higher lipid (fat) content is underway as is the crossing of perennial ryegrass with more droughttolerant fescue to create a new perennial festulolium. Both research programmes are being carried out by the Germinal Horizon team of breeders and scientists at the Institute of Biological, Environmental and Rural Sciences (IBERS) in Wales. Sarah says Germinal’s point of difference has been its Aber High Sugar Grasses which are proven to have a higher water soluble carbohydrate content. That can also help environmentally by
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providing rumen bugs with more energy so they can make greater use of the protein in ryegrass. While Sarah warns that although selecting for higher lipids is going on within the IBERS breeding programme it could be some time before there are any major, concrete results. Standard ryegrass has between 2-4% lipid content and the aim is to increase that to 4-6%.
levels in pastures. Work at IBERS though suggests that increasing the lipid content of grass reduces methane emissions from ruminant livestock by changing rumen fermentation patterns and breaking down protein more efficiently, Sarah says. The Germinal Horizon team at IBERS believes there is potential for increased animal productivity, a decrease in GHG
Slowing down gives rumen microbes more time to make use of the proteins leading to greater nitrogen use efficiency. Work by the New Zealand Pastoral Greenhouse Gas Research Consortium (PGGRC) has reported that higher dietary lipid concentrations in cattle can reduce methane emissions by up to five percent for each one percent increase in lipid content. Much of the work to date has been on manipulating cattle diets using supplements and there’s still work to be done on testing the effects of lifting lipid
emissions, particularly methane, benefits in animal health and fertility and benefits for meat quality and healthy eating. Sarah says the breeding of higher lipid grass at IBERS is done using conventional plant breeding techniques. Those conventional breeding techniques have also been used to breed the festulolium AberRoot by crossing a high sugar perennial ryegrass with a fescue from North Africa.
Dairy Exporter | www.nzfarmlife.co.nz | November 2021
