AR37 vs. other endophytes

AR37 vs. other endophytes

These descriptions provide an overview of some of the commercially available endophytes. Careful consideration should be given to which endophyte is best suited to your farming practice.

Ryegrass containing standard endophyte (also called wild-type or high)

Standard endophyte is the naturally occurring endophyte in perennial ryegrass and has evolved over thousands of years to aid survival. It produces the toxic classes of the alkaloids lolitrem B and ergovaline, which are primarily implicated in the causes of perennial ryegrass staggers and heat stress. Recent studies have also shown that other sub-clinical effects including summer-autumn illthrift, reduced liveweight gain, reduced milk-production, scours and water intake, which may have considerable impacts on the profitability of grazing systems. Standard endophyte offers some protection against ryegrass pests and a deterrent of grazing. This provides reasonable persistence but animal safety and performance is significantly compromised.

Ryegrass without endophyte (also called endophyte free or nil endophyte)

In some areas, cultivars without endophyte are occasionally used. Such pastures are animal safe and will give excellent animal performance. However, endophyte free ryegrass pastures have been shown to be less productive and less persistent in the many areas where pasture pests are present.


Ryegrass with AR37 endophyte

AR37 is a novel endophyte that takes pasture pest resistance to a new level. AR37 provides resistance to four of the main pasture pests in Australian pastures (Argentine Stem Weevil larvae, Pasture Mealy Bug, Root Aphid and Black Beetle). Ryegrasses with AR37 show improved persistence, with higher tiller densities over time than the same cultivars with nil endophyte or standard endophyte. With higher persistence the need to renew pasture due to poor pasture composition may be reduced. The resulting higher producing sward also has long-term benefits in assisting the maintenance of excellent animal performance. The dry matter benefits of ryegrasses with AR37 are higher in areas with greater insect pressure and/or other stresses.

Ryegrass with AR1 endophyte

Provides a safer pasture than standard endophytes with excellent animal performance while providing a moderate range of insect protection. Ryegrass with AR1 endophyte has demonstrated poor persistence in areas with major insect pest pressure in Australia (primarily due to the presence of Black Beetle and Root Aphid), though persistence is moderately better than ryegrass without endophyte.

Ryegrass with Endo5 endophyte

Pastures with Endo5 (as with AR1) contain no lolitrem B (the main cause of ryegrass staggers), but provide good control of adult Black Beetle, Argentine Stem Weevil larvae, Root Aphid and Pasture Mealy Bug. Ryegrass with Endo5 persists better than ryegrass with AR1 in areas where these pests are present. Cultivars containing Endo5 have been specially bred to produce less ergovaline than many cultivars containing standard endophyte, but may have lower animal performance levels over summer - autumn compared with AR1 and nil endophyte options. Endo5 is still a better proposition than standard endophyte.