As hundreds of North Island farmers prepare to renew their pastures this autumn, they face many important decisions.

But one decision about pasture renewal might be easy.

For the best balance of animal health and insect control, one family of ryegrass endophytes stands out.

With zero risk of ryegrass staggers in dairy cows, NEA endophytes from Barenbrug Agriseeds safeguard your stock and deter New Zealand's most costly pasture pests.


After 30 years of research, and over one million hectares of commercial plantings, marketing manager Graham Kerr says the verdict from farmers is clear: pastures with NEA endophytes are the obvious choice for anyone who values animal welfare and performance.

"Unlike some other endophytes, NEA endophytes look after your stock. They have excellent animal performance with no risk of staggers in dairy cows, and a very low risk of staggers in sheep or deer.

"They're also effective against pests like Argentine stem weevil, black beetle and root aphid."

Kerr says the science behind NEA endophytes tells a consistent and compelling story.

Between 1999 and 2018, 21 separate animal safety trials have been conducted, each lasting eight weeks at the height of summer, when the adverse health effects of some endophytes, such as ryegrass staggers and ill-thrift, are most likely to manifest. Stock weights, growth rates and health are frequently assessed in these intensive, replicated trials.

Similarly Barenbrug Agriseeds has run many dozens of field trials throughout New Zealand as well as 18 separate insect bioassays to measure insect protection and pasture persistence.

"A lot of people are surprised when they realise just how much testing has been conducted over the past 20 years into NEA endophytes," he says.

"Endophyte science and research is hugely important because of the sustainable, environmentally friendly solutions it provides for the New Zealand farming industry as a whole. Endophytes are a naturally adapted insect control mechanism, reducing the need for pesticides.


"Our aim has always been to get the best out of endophyte in terms of animal health, while maintaining strong control across a range of insect pests. This is a balancing act, which we believe we have successfully achieved."

By comparing how different endophytes stack up in each of these categories, it's easy for farmers to work out which ones allow them to do best by their livestock at the same time as protecting their pastures.

AR1 endophyte, for example, has very good animal performance and health. But it is weak against black beetle and root aphid.

Overall AR37 endophyte has very good control of key pests. However, the chemicals it produces are not always animal friendly. It is not suitable for deer or horses, and can cause severe staggers in sheep and lambs.

"We believe NEA endophytes provide the solution that bridges this gap," Kerr says. "They have an outstanding animal safety record, and good control of key pests to support pasture persistence."

NEA2 endophyte is available in Trojan and Rohan perennial ryegrasses. NEA comes in Shogun hybrid ryegrass, and Barenbrug Agriseeds' newest endophyte, NEA4, comes in Viscount tetraploid ryegrass.