In New Zealand, Crown Research Institute AgResearch has been making steady progress on the development of a new-generation high-metabolizable energy (HME) ryegrass.
AgResearch said the project's principal scientist, Dr. Greg Bryan, returned from the U.S., where field trials are being conducted on the genetically modified 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 among 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, AgResearch said in an announcement.
“Our ryegrass research has generated high levels of public and scientific interest here in New Zealand and overseas, and now is a good time to provide an update on the progress we are making,” Bryan said. “The HME ryegrass has performed well in controlled growing conditions, and I’ve recently returned from the United States, where we are growing the plants in field trials in competition with one another, just as they would in pasture, and the plants are doing well.
“We’re breeding the best novel traits into ryegrass cultivars that will best suit New Zealand growing conditions, and we’re also introducing genes into the plants that have simpler genetic patterns that will make future breeding programs easier," he said. "The ultimate goal of the United States 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, Bryan issued a note of caution. “This is complex long-term research, and we are 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,” he said.
“It’s important to stress that the forecast environmental benefits associated with the grass need to be supported by rigorous research," Bryan added. "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. Eventually, we will need to seek regulatory approval for HME ryegrass to be grown here in New Zealand for livestock grazing trials. We need to test in New Zealand conditions using New Zealand animals to ultimately confirm or refute the potential environmental and productivity benefits of HME ryegrass.”
DairyNZ is investing farmers’ levies alongside AgResearch to support the trials in the U.S.
Dr. Bruce Thorrold of DairyNZ said, “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.”