AgResearch’s development of a new generation grass is making steady progress, according to the organisation’s principal scientist Dr Greg Bryan.

He’s recently visited the United States where the Crown Research Institute is conducting field trials of the genetically modified High Metabolisable Energy, HME, ryegrass.

New Zealand forage scientists have been conducting experiments to find out whether this new potentially environmentally sustainable grass – one that strikes a balance between reductions in greenhouse gas emissions, greater tolerance to drought and farm productivity – will perform in the field in a similar way to how it performs in controlled environment studies.

“Our ryegrass research has generated high levels of public and scientific interest here in NZ and overseas and now is a good time to provide an update on the progress we’re making,” says Greg. 

“The HME ryegrass has performed well in controlled growing conditions,” says Greg, who saw the plants in the US field trials in competition with one-another, just as they would in pasture. “And the plants are doing well.”

Best novel traits

“We’re breeding the best novel traits into ryegrass cultivars that will best suit NZ growing conditions and we’re also introducing genes into the plants that have simpler genetic patterns that will make future breeding programmes easier.

“The ultimate goal of the US phase of the research is to conduct realistic rather than simulated animal nutrition studies so we can evaluate whether the grass might have the potential environmental benefits, such as reduced methane emissions and reduced nitrogen excretion, that our modelling suggests it will.” 

While the results have been encouraging, Greg is also issuing a note of caution.  “This is complex long-term research and we’re working on a species with challenging genetics.

“It takes several years to breed the HME trait into elite ryegrass varieties currently used by farmers, and very importantly, to test performance every step of the way.

“It’s important to stress that the forecast environmental benefits associated with the grass need to be supported by rigorous research.

“We have a good understanding of the potential benefits of the grass because of our institutional expertise in animal nutrition, from animal nutrition models, and from the biochemical analysis of the grasses in in vitro (test tube) studies.”

Greg says eventually they will need to seek regulatory approval for HME ryegrass to be grown here in NZ for livestock grazing trials. “We need to test in NZ conditions using NZ animals to ultimately confirm or refute the potential environmental and productivity benefits of HME ryegrass.”

World-leading science

DairyNZ is investing farmers’ levies alongside AgResearch to support the trials in the US.

DairyNZ’s Dr Bruce Thorrold says dairy farmers are looking for new ways to reduce their environmental footprint and improve productivity.

“The science done by AgResearch to develop these plants is world-leading, and we’re investing to see how these plants perform in the field and test their potential value for our farmers. While there is a long way to go, we’re encouraged by the results to date.”

AgResearch, in support of this project and a number of other forage-related research initiatives, is also investing in new state-of-the-art glasshouse facilities on their Grasslands campus in Palmerston North.

The glasshouses, designed to precise performance specifications and biosecurity standards, will be used to research novel ryegrass, clover, endophytes and many other forage-related species. 

The Plant Biotechnology Team’s science team leader Dr Richard Scott says the glasshouses have very sophisticated climate control and irrigation technology – “but the big game-changer for us is that their design will allow us to grow plants that produce higher quantities of high-quality seed”. 

New facility

“This new facility is very important for the HME ryegrass programme as all seed used in the US trials is produced here in these contained glasshouses, and we’ll need kilograms of seed to plant enough ryegrass to perform meaningful animal nutrition studies.” 

Up to a dozen scientists from two teams – Plant Biotechnology and Plant-Microbe Interactions – will be conducting various experiments in the glasshouses. “A diverse range of scientists can work together there, including PhD students, so we’re expecting to see even greater collaboration between teams, research institutes, universities, and co-funders,” says Richard.

“We also know this new facility will enable us to increase the scope and pace of both our field trials and the fundamental research programmes into understanding the mechanisms underlying the higher growth rates observed in the HME ryegrass.”