MaxQ development
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
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