|Novel Endophyte Tall Fescue|
It was only a little more than ten years ago scientists began to use the term "novel endophyte" in connection with tall fescue. It describes tall fescue containing a desirable endophyte (internal fungus). This is in contrast to the wild, toxin-producing (and thus undesirable) endophyte usually present in the ‘Kentucky 31’ fescue variety dominating tall fescue acreage in Alabama and the United States. Toxic endophyte fescue results in animal gains commonly 50 to 100 percent lower, and reproductive efficiency that may be more than 30 percent lower, than occurs with non-toxic fescue.
It was the late 1970s when it was discovered (thanks largely to Auburn University research) most of our fescue contains a toxin-producing fungus, to which the animal disorders fescue foot, fat necrosis and fescue toxicity have been linked. It was quickly found that it was an easy matter to remove the fungus from fescue seed and the fungus was only transmitted through seed. Consequently, by the early 1980s fungus-free fescue seed became commercially available. Animal performance on fungus-free fescue was excellent, but it soon became painfully clear that fungus-free fescue does not persist well in Alabama.
In the 1990s, New Zealand scientist Dr. Gary Latch identified several endophyte strains that do not produce the toxins associated with animal disorders and poor animal performance, but did produce the compounds that result in good persistence of fescue. One of these was inserted in fescue varieties named ‘Jesup’ and ‘Georgia 5,’ developed by University of Georgia plant breeder Dr. Joe Bouton, and these varieties began to be marketed under the name "Max Q" in 1999.
Subsequently a novel endophyte named "ArkPlus" was developed through cooperative work by scientists at the University of Arkansas and the University of Missouri and was marketed for a short while. Another novel endophyte named "Fletcha" is now being marketed in states west of Alabama, one named "BarOptima" is just coming available, and one inserted in Kentucky 31 (no commercial name announced yet) is expected within a year or two.
Novel endophyte fescue has now been around for years, and here is what we can say about how it has performed. First, there have been no fescue-related animal disorders associated with novel endophyte tall fescue. Second, animal gains and reproduction are as good as obtained with animals consuming fungus-free tall fescue. Third, persistence (even through the recent severe droughts) has been similar to that of Kentucky 31. Much research data and lots of producer experience back up these statements.
Close to a half million acres of novel endophyte tall fescue have been planted in the United States. However, in view of the dramatically higher animal production potential on this type of fescue, it seems there should have been even greater acceptance and use. By comparison, in New Zealand, novel endophyte perennial ryegrass varieties (which became available only a few years before novel endophyte fescue was introduced in the USA) now occupy over 80 percent of the acreage of that grass in that nation.
What explains the difference in the level of acceptance of novel endophytes in New Zealand versus the USA? There probably are several reasons. Regardless, it is clear the potential of increasing our novel endophyte fescue acreage constitutes a great opportunity we have for substantially increasing animal production in the future. In fact, it can be argued development of novel endophytes is one of the most important (perhaps the most important) forage research achievements in history. The economic implications of this technology for livestock production are immense.
Don Ball is an Extension Forage Crop Agronomist with Auburn University.