Tall fescue, grown on more than 35 million acres (the "tall fescue belt"), is the most widely spread pasture grass in the humid areas of the eastern USA (Stuedemann & Hoveland, 1988)..

The Problem and the Opportunity:

Tall fescue, grown on more than 35 million acres (the "tall fescue belt"), is the most widely spread pasture grass in the humid areas of the eastern USA (Stuedemann & Hoveland, 1988). For tall fescue in southeastern USA, long term persistence, competitiveness, yield, and survival after summer drought are directly related to the presence of the Neotyphodium coenophialum fungal endophyte living in the fescue plant (Glenn, Bacon, Price & Hanlin, 1996). 95% of all tall fescue pastures in the USA are infected with the endophyte (Shelby & Dalrymple, 1987). Summer drought results in the greatest death of tall fescue stands in the southeast. Tall fescue cultivars infected with their endemic N. coenophialum endophyte (E+) demonstrate much better survival in very hot, dry summers than the same cultivars with their endophyte (E-) removed (Bouton et al. 1993).

Cattle for meat production is the principal class of livestock grazing pastures in the tall fescue belt (Hoveland, 1986). Over 10 million breeding cows for meat production are pastured in the tall fescue zone. This represents one-third of the total US beef cowherd (USDA Census of Agriculture, 1997). Weaned calves and feeder cattle are raised on tall fescue pastures and shipped west to the Plains states to background, feedlot and process to meat products.

Cattle grazing forage from most tall fescue cultivars infected with their endemic N. coenophialum endophyte (E+) suffer from a condition called "fescue toxicosis" (Morgan-Jones & Gams, 1982). Fescue toxicosis occurs as a result of ingestion of ergot alkaloids derived from the endophyte association (Hill et al., 1994). Toxicosis symptoms expressed include poor weight gains due to reduced grazing, retained hair coats, evidence of excessive heat stress, poor milk production, and reduced reproduction in afflicted animals (summer slump), loss of ear tips, tail switches and hooves (fescue foot), and bovine fat necrosis (Hoveland et al, 1983; Schmidt & Osborne, 1993; Stuedemann and Thompson, 1993). Ergovaline is the most abundant and potent of the ergopeptine alkaloids produced by E+ tall fescue and is considered to be the most likely causative agent of fescue toxicosis (Oliver, 1997).

The annual financial loss by beef cattle producers in the tall fescue belt caused by fescue toxicosis includes US$255 million in reduced weaning weights and US$354 million in reduced calf numbers (Hoveland, 1993). To these should be added an annual loss of around US$400 million in reduced weights of feeder cattle shipped to feedlots, and old cull beef cows sold for slaughter. Estimated total annual losses to beef producers caused by fescue toxicosis are around US$1 billion.

Therefore, livestock producers have been presented with the dilemma of whether to retain E+ tall fescue pastures for their stand persistence, and suffer reduced animal performance due to the inherent toxins, or grow E- tall fescue pastures to improve livestock performance, but risk loss of the pasture stand within 2-5 years after establishment.

Development of Novel Endophyte Tall Fescue:
AgResearch in New Zealand in collaboration with the University of Georgia, USA pursued the novel approach of identifying and selecting naturally occurring, non-toxic endophyte strains for later re-infection into elite tall fescue cultivars (Latch, 1997). AgResearch’s endophyte research group screened hundreds of strains of endophyte to identify those that expressed nil production of toxic ergovaline and moderate to high levels of beneficial peramine and loline alkaloids.

The University of Georgia developed and released two tall fescue cultivars, Georgia 5 and Jesup, for use in southeastern USA (Bouton et al. 1993b; Bouton et al. 1997). Their excellent agronomic performance when infected with endophytes (Bouton et al. 1993a) made them good candidates for the strategy of killing the toxic resident endophyte in their seeds and re-infecting their seedlings with non-toxic (i.e. nil ergot producing) endophytes. Patented, non-toxic N. coenophialum strains (Latch et al. 2000) were re-infected into a random sample of several hundred seedlings of endophyte-free (E-) Jesup and Georgia 5 tall fescue using procedures of Latch and Christensen (1985). Several strains were assessed for host compatibility, nil ergot alkaloid production, endophyte transmission between plant and seed, and agronomic performance (Bouton et al. 2000; Bouton et al. 2002). MaxQ® emerged from these tests as particularly successful.

Two new products, Jesup MaxQ® and Georgia 5 MaxQ®, are combinations of superior tall fescue forage grass cultivars (Jesup and Georgia 5) and a revolutionary non-toxic endophyte (marketed as MaxQ®), revolutionary in the sense of novelty of the technology and size of impact on forage and livestock performance. Pennington Seed Inc of Madison, Georgia markets Jesup MaxQ® and Georgia 5 MaxQ® in the USA.

Benefits and Financial Impact of MaxQ® on Forage and Meat Production

Potential persistence and stand life were estimated by designing and installing a novel method of accelerating the aging of tall fescue pastures (Bouton et al. 2001b). Three versions of Jesup and Georgia 5 (E+, E-, and MaxQ®) were interseeded into bermudagrass (Cynodon dactylon L.) sod and grazed with beef cattle. Continuous grazing combined with bermudagrass competition and extreme summer drought were very stressful and allowed E+ and E- cultivars to be separated quickly and efficiently. After four years the E+ and MaxQ® versions of both cultivars exhibited stand survival superior to the E- checks. Only Jesup MaxQ® was still found to possess stands equivalent to the E+ checks (Bouton et al, 2000; Bouton et al. 2002). This test indicates that Jesup MaxQ® pastures will persist as long as Jesup E+ tall fescue pastures.

The performance of beef cows and calves and feeder cattle grazing Jesup MaxQ® and Georgia 5 MaxQ® were compared against E+ and E- Jesup in central and north Georgia, USA over a 2 year period. The feeder cattle were then transported to Stillwater OK to be raised in feedlots, followed by processing and carcass assessments at Garden City KS. The results of this testing program can be summarized as follows (Bouton et al, 2001b):

• Jesup MaxQ® and Georgia 5 MaxQ® produced nil ergot alkaloids in their forage.
• Animals consuming E- or MaxQ® forage did not exhibit the depressed serum prolactin of animals consuming E+ forage, and did not exhibit symptoms of fescue toxicosis.
• At weaning heifer calves grazing MaxQ® enhanced pastures weighed an extra 37 lb live weight (value US$30 extra per calf) compared to heifer calves grazing Jesup E+ tall fescue.
• Similarly, at weaning steer calves grazing MaxQ® enhanced pastures weighed an extra 94 lb live weight (value US$75 extra per calf)
• Similarly, at the completion of the stocker grazing phase, feeder cattle (heifers and steers) were 116 lb heavier (value US$93 extra per animal)
• At the completion of the feedlot phase, live cattle (heifers and steers) that were backgrounded on MaxQ® enhanced pastures were 108 lb heavier.
• After processing and grading, the carcass value was US$108 higher per animal on average.

Up to 2001, these new tall fescue products have been planted on more than 15,000 acres on commercial beef production properties and on research stations in eastern USA. A major portion of the tall fescue belt is suitable for removal of the toxic E+ tall fescue pastures and replacement with MaxQ® pasture products. The new products have quickly gained a reputation among beef producers of fitness for purpose, quick payback on investment, and excellent financial gains to producers.

Publications associated with Novel Endophyte Tall Fescue:
Bouton, J.H.; Hill, N.S.; Hoveland, C.S.; McCann, M.A.; Watson, R.H.; Parish, J.A.; Hawkins, L.L.; Thompson, F.N.; Latch, G.C.M. 2002. Re-infection of Tall Fescue Cultivars with Non-Ergot Alkaloid Producing Endophytes. Agronomy Journal. In press
Bouton, J.H.; Hill, N.S.; Hoveland, C.S.; McCann, M.A.; Thompson, F.N.; Hawkins, L.L.; Duckett, S.K.; Parish, J.A.; Watson, R.H.; Andrae, J.G.; Gill, D.; 2001b. Georgia State Report to SERAIEG Group 8, Chapel Hill TN, USA November 5-6, 2001. pp. 9-20
Bouton, J.H.; Hill, N.S.; Hoveland, C.S.; McCann, M.A.; Thompson, F.N.; Hawkins, L.L.; Latch,
G.C.M. 2000: Performance of tall fescue cultivars infected with non-toxic endophytes. Proceedings of the 4th International Neotyphodium/ Grass Interaction Symposium. 27-29 September 2000. Soest, Germany. (eds. V.H. Paul and P.D. Dapprich) pp. 179-185.
Bouton, J.H.; Hill, N.S.; Hoveland, C.S.; McCann, M.A.; Thompson, F.N.; Hawkins, L.L.; Latch,
G.C.M. 2000: Infection of Tall fescue Cultivars with Non-toxic Endophytes.
Proceedings of the 55th Southern Forage Crop Improvement Conference, Raleigh NC, June 12-14, 2000. URL: http://clay.agr.okstate.edu/spfcic/procedures/proceed.htm General Program.
Bouton, J.H.; Hill, N.S.; Hoveland, C.S.; McCann, M.A.; Thompson, F.N.; Hawkins, L.L.; Latch,
G.C.M. 2000: Tall fescue Cultivars Infected with Non-toxic Endophytes.
Proceedings of the 2000 American Forage & Grasslands Conference. 16-19 July 2000. Madison WI. (eds. Mike Philips and Thomas Terrill) pp. 125-129
Bouton, J.H.; Duncan, R.R.; Gates, R.N.; Hoveland, C.S.; Wood, D.T. 1997. Registration of ‘Jesup’ tall fescue. Crop Sci.37: pp. 1011-1012
Bouton, J.H.; Gates, R.N.; Belesky, D.P.; Owsley, M. 1993a. Yield and persistence of tall fescue in the southeastern coastal plain after removal of its endophyte. Agron. J. 85:52-55.
Bouton, J.H.; Gates, R.N.; Hill, G.M.; Owsley, M.; Wood, D.T. 1993b. Registration of 'Georgia 5' tall fescue. Crop Sci. 33:1405.
Fribourg, H. A., Waller, J. C., Latch, G. C. M., Fletcher, L. R., Easton, H. S., Stratton, A. E. 2002. Evaluation under grazing of Festuca arundinacea cultivars infected with nontoxic endophytes. pp 530-531 in Proceedings 19th Congress European Grassland Federation. La Rochelle, May 2002.
Hiatt, E.E., III, N. S. Hill, J. H. Bouton, and C.W. Mims. 1997. Monoclonal antibodies for detection of Neotyphodium coenophialum. Crop Sci. 37:1265-1269.
Hiatt, E.E., N.S. Hill, J.H. Bouton, and J.A. Stuedemann. 1999. Tall fescue endophyte detection: commercial immunoblot test kit compared with microscopic analysis. Crop Sci. (39:796-799).
Lane, G.A.; Tapper, B.A.; Davies, E.; Christensen, M.J.; Latch, G.C.M. 1997: Occurrence of
extreme alkaloid levels in endophyte-infected perennial ryegrass, tall fescue and meadow
fescue. Proceedings of the Third International Symposium on Neotyphodium/Grass
Interactions. Athens, GA. USA. Plenum Press. pp. 433-436.
Latch, G.C.M.; Christensen, M.J.; Tapper, B.A.; Easton, H.E.; Hume, D.E.; Fletcher, L.R. 2000. Tall fescue endophytes. United States Patent 6,111,170 issued 29 August, 2000. United States Patent & Trademark Office. URL: www.uspto.gov
Latch, G.C.M. 1999: Neotyphodium-grass interactions and their economic importance. In:
Proceedings of the International Symposium of Mycotoxicology 1999. Mycotoxin Contamination Health Risk and Prevention Project. Chiba, Japan. Supplement ’99 pp 116-
117.
Latch, G.C.M. 1998: Grass endophytes as a model. Sydowia 50: 213-228.
Latch, G.C.M. 1997: An overview of Neotyphodium/grass interactions. Proceedings of the Third
International Symposium on Neotyphodium/Grass Interactions, Athens, GA, USA. Plenum
Press. pp. 1-11.
Latch, G.C.M. & Christensen, M.J. 1985. Artificial infection of grasses with endophytes. Ann. Appl. Biology. 107: 17-24.