A new variety of ryegrass could help New Zealand farmers significantly boost milk and meat production while also lowering methane emissions.
Agricultural seed company Germinal is developing ryegrass with increased lipid (fat) content, along with its research partner, the Institute of Biological, Environmental and Rural Sciences (IBERS) in Wales.
Theobjective is to make the feed more energy-dense, improving milk production in dairy cows and growth rates in beef and sheep.
The high lipid grass is being developed using conventional plant breeding methods, with no gene editing or modification required.
"Lipids, in other words fats and oils, have roughly double the energy value of carbohydrates for the same weight" said Germinal New Zealand General Manager Sarah Gard.
"We've known for a long time that adding fats – up to a certain level – increases animal productivity. But non-pasture feed supplements are generally expensive, which can offset any gains in milk solids or revenue.
"However, if the pasture has higher concentrations of lipids, the grazing animal naturally has a high intake without the need for supplements. Stock will get extra fats directly from the grass."
Germinal hoped to breed ryegrass with a lipid concentration of five per cent – double that found in current varieties.
The benefits could also extend beyond animal performance, with lab tests indicating that high lipid grass can mitigate climate change by reducing greenhouse gas emissions.
Germinal New Zealand General Manager Sarah Gard. Photo / Supplied
"The work being done at IBERS has shown that increasing the lipid content of grass reduces methane emissions from ruminant livestock, by changing rumen fermentation patterns and breaking down protein more efficiently" said Gard.
"We hope to extend this work in the near future by feeding sheep with high lipid grass and then measuring how much methane they produce."
New Zealand's Pastoral Greenhouse Gas Research Consortium (an industry/government joint venture group) reported that higher dietary lipid concentrations in cattle can reduce methane emissions by up to five per cent for each one per cent increase in lipid content.
Germinal's focus on lipids is the next step in its ryegrass breeding programme. The company has established a research and development station in Christchurch, which is supported by on-farm trials throughout New Zealand.
"Our focus until now has been on increasing the water-soluble carbohydrate (sugar) content, leading to the development of our high sugar grasses which have developed a strong market in New Zealand," said Gard.
"If we are to continue improving the nutritional value of grass available to farmers then we need to look at other components, such as lipids. This project has the potential to develop a new generation of grass to help farmers be both more sustainable and productive, with positive flow-on effects for the industry as a whole."
