American Endurance Ride
Conference
BOARD OF DIRECTORS MEETING
held via telephone
conference call
March 7, 2005
President C. Mike Tomlinson called the
meeting to order at 6:02 pm. Also on the line for the call:
Treasurer Terry Woolley Howe, Mike Jaffe, Roberta Harms, Connie Caudill, Howard
Kent, Stan Eichelberger, Patti Pizzo, Gail Williams, Bob Morris, John Parke,
Duane Barnett, Randy Eiland, Jim Baldwin, Dane Frazier, Mike Maul, Stagg
Newman, Maggy Price, Robert Ribley, and Executive Director Kathleen A.
Henkel. Absent: Vice President Susan Kasemeyer; Secretary Jan
Jeffers; Vonita Bowers; Jan Stevens; Roger Taylor; Nick Warhol; Barney Fleming.
It was moved by Connie Caudill and seconded
by Mike Maul to excuse Roger Taylor (out of the country); Jan Stevens
(traveling); Vonita Bowers (traveling); Susan Kasemeyer (family concerns); Jan
Jeffers, Nick Warhol from this call. Motion passed.
It was moved by
Robert Ribley and seconded by Bob Morris to approve the minutes of the February
7, 2005, call as written. Motion passed.
It was moved by
Stan Eichelberger and seconded by Mike Maul to accept the Education and
Research Grants committee reports as written. Motion passed.
Special Sanction Committee Chair Vonita Bowers was unable to make the call and President Tomlinson advised in her absence that the ride managers for the Grand Canyon XP and Owyhee Pioneer rides have agreed to hold their rides even though they overlap by one day this year. Steps will be taken to insure the rides do not overlap next season. No word from Vonita regarding a proposed date change for the Smokey Killen ride, West Region, which also overlapped with the Grand Canyon and Owyhee rides.
Research Grants Committee Chair Bob Morris advised he previously forwarded information regarding a grant from Virginia Tech at Middleburg in the amount of $16,500, presented by T. M. Hess, DVM. Bob Morris advised the committee is in favor of the grant and there is a possibility of some assistance to AERC with the funding for the grant. Motion before the board to seek approval of the grant passed with one abstention, Patti Pizzo. President Tomlinson invited Tom Ackart, facilitator regarding the long range plan to join the call. Tom introduced himself to the board and briefly explained the planning process. It is Tom’s hope to keep the meeting time regarding long range planning to 3 hours on Sunday. Tom encouraged everyone to keep the comments coming regarding the questions posed to the Board by President Tomlinson pertaining to the long-range plan for AERC. Questions from the Board regarding AERC’s long range planning process can be posed to Tom via email or telephone call. A question was raised regarding the recent death of an equine at a ride in the Southwest Region and Jim Baldwin, Chair of the Veterinary Committee, was requested to contact the owner of the equine and discuss necropsy.
Meeting adjourned at 6:36 p.m.
Respectfully
submitted,
Kathleen A. Henkel,
Secretary Pro Tem
Prepared by
Co-chair Stagg Newman
3/2/05
During the last year the AERC
Education Committee continued to expand its education of the AERC members
through:
· print media via Endurance News and direct
mailing,
· through electronic means via the AERC
web page and via co-sponsoring with the Ride Mangers Committee and the Vet
Committee the vet video
· through in person contacts via clinics and by
encouragement of mentorships. We also published guidelines for choosing
mentors in EN.
We also published in Endurance News the long terms educational
objectives and goals for AERC which were incorporated into the Past President’s
recommendations that were presented at the 2004 March Sunday Board meeting.
I. Print media
· A member of the EC published an EN column in
every issue of EN. This year we had articles from most of the members of
the EC. At the suggestion of members we had numerous articles addressed
to experienced riders wishing to improve their horses’ performance in addition
to articles on horse welfare and safety.
· Directly worked with authors who were not
members of the EC to publish at least another dozen educational articles which
originated either because we solicited them or members contacted the Education
Committee
· Reviewed all articles of an educational
nature that were submitted directly to the office
· Send a direct mailing to all AERC
members entitled “Three Keys to Safe Competition
· Published in EN the long term education
objectives and goals for AERC which had been incorporated into the Past
President’s recommendations at the 2004 March Board meeting.
·
II. Electronic Media
· Continued to update the AERC Education
Page on the AERC web site
· Added new material for clinics that can be
downloaded and used by AERC members who are conducting their own clinics.
III. Clinics
· Ann Cofield developed material for and then
conducted a one-day clinic for endurance riders. The material from that
clinic is now posted on the AERC web site for use by all AERC members.
Ann wrote an article for EN entitled “You can do, we can help” to make members
aware of the material and to encourage others to give clinces.
· Stagg Newman developed a clinic on how
to prepare for and ride 100 mile rides and gave this clinic at several rides
this year. The ideas from this clinic were incorporated into EN columns
and the outline is available for use by others.
The AERC Education Committee is now working on two new proposals
for consideration in the future:
· A nominal scholarship award for junior riders
achieving certain milage objectives towards college education. Details of
the proposal, funding requirements, funding source, etc. are still being
developed.
· An on-line educational class on the
physiology, care, and feeding of endurance horses. The course would be
offered through the University of Guelph, which already has similar course in
equine physiology, etc. under the leadership of Dr. Gayle Ecker. The
course would draw on current materials that would be focused on the endurance
horse as well as experts in the endurance horse (vet, riders, nutrionists,
…_) This exciting proposal is in the early stage of formulation.
Prepared by Bob
Morris, Chair
3/2/05
The AERC Research
Grants Committee currently has in place three signed contracts for research to
be funded by the American Endurance Ride Conference. These grants have been
made to the New Bolton Center, Michigan State University and the University of
Wisconsin.
The projects
being conducted by the New Bolton Center and Michigan State have been in
progress for one ride season and the research teams have acquired their initial
data and will be working on it during the winter months. No reimbursement has
yet been made on these contracts and the allocated monies are in reserve
accounts awaiting deliverables.
The third grant approved by the AERC Board of
Directors was just consummated in a signed contract with the University of
Wisconsin. This project will get underway in the proximate months and continue
for an additional season.
A fourth grant
from Va. Tech at Middleburg is currently under consideration for approval.
Information from
the Research being conducted by Michigan State University is being considered
for inclusion in our web pages. It is also the intent of the researchers from
the University of Wisconsin to be linked to our AERC web system for the benefit
of the Membership.
The Research Grants
Committee will continue to prospect for research projects that will be of
benefit to the membership of the AERC, as funds allow.
The following
page provides a short spreadsheet illustrating the full financial status of the
Research Grants Committee allocated funds.
AERC RESEARCH GRANTS
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GRANTEE |
YEAR |
PROPOSED GRANT |
GRANT AMOUNT |
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Michigan State
University |
2004 |
17,000 |
17,000 |
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New Bolton
Center |
2004 |
6,050 |
6,050 |
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University of
Wisconsin |
2005 |
21,528 |
21,528 |
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Va. Tech
Middleburg |
2005 |
16,500 |
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TOTALS |
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61,078 |
44,578 |
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Funds currently
available |
2004 |
45,000 |
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2005 |
??? |
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Total |
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Committed |
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44,578 |
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Balance |
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422 |
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The above table
relates to the current financial status of the AERC Research Grants. In the
fiscal year 2004 the Board approved grants to the New Bolton Center and to
Michigan State University in the aggregate amount of $23,050. The initial seed
allocation to the AERC Research Grants Committee was in the amount of $45,000,
leaving an uncommitted balance of $21,950.
So far in the
fiscal year of 2005, the AERC Board has approved grants totaling $21,528 issued
to the University of Wisconsin, leaving a current balance of $422. We currently
have up for approval in 2005, an additional proposed grant for Va. Tech at
Middleburg amounting to $16,500.
Action on the
Middleburg grant has not been expedited to allow the acquisition of additional
information about related research and also to the fact that available monies
for 2005 have not been determined. Should the grant request be approved by the
AERC Board of Directors it will not be consummated until funds are made
available.
**Middleburg Ag
Proposal:
Do risks of potassium supplementation depend
on speed?
Research Proposal, January 2005 (updated)
T.M.Hess, DVM, MS, PhD
Pratt Fellow in Equine Nutrition, Virginia
Tech
Background:
Fatigue and neuromuscular hyperexcitability are associated with high
concentrations of potassium in extracellular fluid and blood plasma
(1,2). They contribute to poor performance and elimination from endurance
races. A critical review of 7 studies suggested a threshold of 4 m/sec (9 mph)
on the flat for an increase in plasma potassium3. It was
proposed that endurance horses should be provided with potassium-free
electrolyte supplements when speeds of > 4 m/sec had been achieved or were
expected, and with potassium-rich mixtures for slower speeds and immediately
after the event. In general, increase in plasma potassium is proportional
to exercise intensity. 4, 5
Neuromuscular hyperexcitability develops when the negative resting
membrane potential becomes more positive and approaches an activation threshold
when then membrane discharges. During this phase likely clinical
manifestations are heart rate arrythmias, increased gut motility, thumps,
muscle twitches and fasciculations. Further positive change passes the
threshold and the muscle becomes unresponsive, gut motility ceases and skeletal
muscles fatigue is seen as a reluctance or inability to move.
Our first comparison of free- and rich-potassium mixtures in a 50-mile
race indicated that neuromuscular excitability reached a statistically risk
zone in 1 of 171 horses given potassium-rich mixtures but only 1 in 769 in
those receiving potassium-free supplementation. 2 In a
treadmill experiment simulating a 50-mile ride, correspond estimates were 1 in
4 horses and 1 in 18 horses reaching the risk zone.6 In
contrast, in our second actual race, conditions were hotter and more hilly,
horses ran consistently slower than 4 m/sec, plasma potassium declined (instead
of rising) and contraindicated the use of potassium-free mixtures.7
Thus at present we suggest that the rider has decision to make depending on the
horse’s recent and expected intensity of effort.
One weakness in this series of studies has been the failure to observe
clinical signs of neuromuscular excitability. The most likely would be
heart arrhythmias that could be detected objectively by electrocardiography.
PROGRESS RESULTS SUPPORTERS
AERC PROPOSAL
Background
Neuromuscular hyperexcitability is manifested during endurance races as
heart rate arrythmias, muscle twitches and fasciculations, irregular gut
motility and a lower performance. The resting membrane potential is
determined mainly by the distribution of potassium ions across the muscle
membrane. The concentration of potassium inside the cell is much higher
(about 124 mEq/L) than the concentration outside the cell (about 4
mEq/L). During exercise at speeds greater than 4 m/s (9 mph) on the flat
plasma potassium concentration will increase despite sweat losses.
Increases in plasma potassium will change he ratio of extra-cellular: to
intra-cellular potassium increasing the resting membrane potential, increasing
neuromuscular excitability.
Threshold potential is the level of depolarization any stimulation has
to reach in order to initiate a muscle contraction. The resting potential
is about 15 mV below the threshold potential. The calcium ions are the
main responsible for the threshold potential. During endurance races low
plasma calcium is commonly seen. It decreases the threshold potential and
increases neuromuscular excitability because the threshold potential gets
closer to the resting membrane potential. Low plasma calcium is caused by
metabolic alkalosis, which is also a common finding during endurance
races. Certain diets rich in potassium and or sodium have a high cation-anion
difference (i.e. high pasture and hay). These diets can lead to chronic
alkalosis. When an endurance horse exercises, alkalosis will be
exacerbated under these diets and with electrolytes rich in potassium and
sodium. Electrolytes rich in sodium and chloride help to reduce cation-anion
difference and attenuate alkalosis, mainly chloride supplements. Clinical
signs associated with low calcium are heart rate arrythmias, thumps, and
abnormal gut motility. The combination of high plasma potassium and low
plasma calcium may exacerbate clinical signs associated with neuromuscular
hyperexcitability.
Research
Results
Plasma potassium concentrations increased during the first Middleburg Research
Ride at average speeds of 3.3 m/s (7.4 mph) over hilly terrain. Plasma pH
increased at the first vet check (horses became alkalotic) and decreased at 50
miles and recovery (horses became acidotic). Supplementation with
potassium-free, sodium rich electrolytes attenuated acidosis at the end of the
ride. Lower plasma potassium was found in the potassium-free supplied horses at
80 km, which may lead to less neuromuscular hyperexcitability.
During the second Middleburg Research Ride results confirmed that potassium
supplementation affects plasma potassium concentrations. Lower plasma potassium
concentrations were seen in potassium-free supplied horses. However,
average speed was only 2.8 m/s (6.3 mph) over hilly terrain and increases in
plasma potassium concentrations were not seen. Horses supplied with
two experimental feeds had higher calcium concentrations than horses supplied
with commercial feeds. Horses supplied with potassium–free electrolyte
formulas also had higher calcium concentrations than horses supplied with
potassium rich electrolyte formulas. Horses on the experimental feeds
also were less alkalotic than horses on commercial feeds, leading to the higher
calcium concentrations. Three eliminated horses had heart rate arrythmias
and a labile heart rate. These horses had higher plasma potassium and
lower plasma calcium levels compared to finishers.
The third experiment was 50-mile simulated endurance ride on the
treadmill. The experiment confirmed that potassium supplementation
affects plasma potassium concentrations. Horses on potassium-rich
electrolytes had higher potassium plasma concentrations during exercise and had
a much greater chance to have clinical signs associated with increased
neuromuscular excitability. Resting electrocardiograms were done and no
differences were seen between the two electrolyte supplemented groups.
The fourth experiment was a treadmill experiment with horses exercising at
higher speeds (13.4, 15.7 and 18 mph) for shorter distances. At these
speeds plasma potassium concentrations are higher and horses are more likely to
reach plasma potassium levels that will increase neuromuscular
hyperexcitability. Horses supplied with potassium rich formulas had
higher plasma potassium concentrations, and were at much higher risk to have
clinical signs associated with neuromuscular hyperexcitability. Horses
supplied with potassium-free electrolyte formulas had higher plasma calcium
concentrations than horses supplied with potassium rich formulas. Also
horses supplied with potassium rich formulas had higher plasma lactate,
indicating more anaerobic metabolism and could indicate more fatigue.
In summary, the experiments clearly demonstrated that supplementation of
potassium-free electrolytes will lead to lower plasma potassium concentrations
during exercise. Higher plasma calcium concentrations were also found in
potassium-free supplemented horses. Lower plasma potassium and higher
plasma calcium concentrations will reduce the risk of clinical signs related to
increased neuromuscular hyperexcitability.
Objectives:
The general objective is to improve the care and performance of the
endurance horse by administration of water and electrolytes during, after and,
perhaps, before an event.
Specific objectives are to compare the effects of potassium-free and
potassium–rich mixtures on (a) plasma concentrations of potassium ions and
heart arrhythmias (palpitations, monitored by electrocardiography), and (b)
plasma concentrations of potassium ions hydrogen ions (acidity), especially in
relation to a fatigue, and possibly a new form of reluctance to move
(‘tying-up’).
To increase the likelihood of observing heart changes and fatigue, we
will run horses at higher speeds on the treadmill than we have
previously.
Experimental design and
protocol:
The effects of two electrolyte replacement
formulas, one potassium-rich (EM+K) and one potassium-free (EM-K) will be
tested during an exercise test on the treadmill.
Horses
Thirteen horses Arabian and Arabian cross-bred
will be trained for 20 weeks prior to the test.
Electrolyte composition
K free formulas will contain 21.8 g of sodium
chloride, 1.7 g of calcium chloride, 1.1 g of magnesium chloride, and 0.13 g of
monosodium monophosphate per dose. Potassium-rich formula will contain
21.8 g of sodium chloride, 1.7 g of calcium chloride, 1.1 g of magnesium
chloride, 13.31 g of K acetate and 0.13 g of monosodium monophosphate per dose.
Two doses will be supplied one hour prior to
exercise start, and 2 more doses at 19 minutes of every rest stop, as well as
after finishing the test.
Exercise test
Thirteen horses will be submitted to three
exercise bouts of 7 miles at an exercise intensity of 4, 5, and 6 m/s at 3o
incline (6%). At every bout start horses will be warmed up for 5 minutes
at 1.8 m/s on a flat TM before being submitted to the 4, 5, and 6 m/s intensity
exercise. Horses will be cooled down for 5 minutes at the end of each loop
walking at 1.8 m/s. Rest stops (R1, R2) of 20 minutes will be provided at
the end of each bout where electrolytes will be administered orally at 19
minutes of the resting period and water will be available during the 20 minutes
of rest.
Two baseline blood samples will be taken in
the morning before the first dose of electrolytes is administered. The other
samples will be taken five minutes before exercise starts, after 5 minutes of
walk, at five minutes of trot (canter) and every 10 minutes during the trot
(canter) until the five minute cooling down starts (B11, B12, B13, B14; B21, B22,
B33, …, B3NN) and at 0, 5, 10 and 19 minutes of every rest period (R11, R12,
R13 R21, …, R23). At the end of BI and B2, horses will be walked at 1.8
m/s for 5 minutes and a blood sample will be taken 1 and 5 minutes of
walking. After the end of B3 horses will be cooled down (C) walking
at 0o incline for 10 minutes and 2 blood samples will be taken every
5 minutes during this period (CD1, CD2). Recovery will start after the
cool down period. Blood samples for the recovery period will be taken at
0, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, 120, 180 minutes and in the morning
after the test.
Horses will be acclimated and trained to
exercise on the treadmill before the test. The electrolytes will be supplied
two hours before, and at 15 minutes of every rest period, as well as 10 minutes
after the end of the exercise test. The horses will be weighed before, at
the end of every bout and at 19 minutes of every rest period, at 30, 60, 180
minutes after, and the morning after the test. During the ET recovery
time, the horses will be allowed to have access to water and hay.
EKGs will be monitored during the exercise
phase with a digital Holter recorder. Data will be sent to Penn State for
analysis. Any abnormalities in the EKG s will be assessed.
Dependent variables:
Blood will be collected from catheterized
jugular veins into blood gas syringes will be analyzed on the Nova Blood gas
machine for the determination of: hematocrit and hemoglobin; glu, lac, pH, Na,
K, Cl, Mg, PCO2, PO2, BUN. Blood from the heparinized
tubes will be centrifuged at 3000G for 10 min and analyzed for PO4,
TP and alb.
Statistical Analysis:
ANOVA repeated measures in a mixed model for the blood and plasma samples
comparing the effects of the two electrolyte
mixtures.
Likely outcomes
Plasma concentrations of potassium and hydrogen ions will be less elevated at
high speeds in horses give potassium-free electrolytes mixtures, thereby
reducing the risks of heart disturbances and muscle fatigue.
Bibliography:
3. Kronfeld, D.S. 2001. Body fluids and exercise:
replacement strategies. J Equine Vet Sci 21:368-375.
4. Harris, P.; Snow, D.H. 1992. Plasma potassuim and lactate
concentration in Throughbred horses during exercise of varying intensity. Equine
Vet. J., 23:220-224.
5. Gottlieb-Vedi, M., K.Dahlborn, A.Jansson,
and R.Wroblenski. 1996. Elemental composition of muscle at rest and
potassium levels in muscle, plasma and sweat of horses exercising at 20oC
and 35oC. Equine Vet. J. Suppl. 22:35-41.
6. Hess,T.M., K. Treiber, D.S. Kronfeld ,
J.E. Waldron, C.A.Williams, M. S. Freire, A.M.G. Braga , L.S. Gay
, and P.A. Harris. Potassium supplementation affects plasma [K+]
during a simulated 80-km endurance test on the treadmill. J Anim Sci 2004;
82 (suppl. 1):97.
7. Hess, T.M., K. Greiwe-Cradell, D.S Kronfeld,
J.E. Waldron, C.A. Williams, M.A. Lopes, R.M. Hoffman, L.A.Gay, D. Ward, and
P.A. Harris. Potassium-free electrolytes and calcium supplementation in
an endurance race. Proceedings of the Eighteenth Equine Nutrition and
Physiology Symposium, East Lansing, MI, June4-7, 2003, 18:148-149.
Budget:
Blood gas analyzer reagents
$ 6000.00
Beckman analyzer reagents
$ 3000.00
Syringes, blood
tubes
$ 700.00
Computer services, statistical
consulting
$ 800.00
Holter recorder, 3
units
$ 6000.00
TOTAL
$
16500.00