One of very important prerequisites for achieving good results in races, in
addition to genetic predisposition, quality training and good health, are
optimal values for number of erythrocytes, concentration of haemoglobin and
hematocrit, of which depends efficient oxygen supply of muscles during great
efforts. The stated values, along with data on heart rate, are useful
indicators of the degree of horse fitness and readiness for horse race. The
influence of physical exertion on the values of basic hematological
parameters as well as on heart rate, was investigated on 6 trotters, in
training at the Belgrade racetrack (one head of Italian trotter, male, 3
years old; 3 heads of American trotter, male, 3,4 and 6 years old and two
heads of Serbian trotter, female, 4 and 5 years old). The blood samples for
hematological tests were taken by punction of jugular vein in resting phase
- immediately before the commencement of work, after light trot warming for
3000 m and fast trot for 1000 m, with 30 minutes rest between the two
runnings. The heart rate was monitored continuously by radio telemetry
cardiometer, from the moment they were taken from their boxes and harnessing
to the completion of work. The obtained results confirm the relationship
between the rise of heart rate and hematocrit values: maximal hematocrit
values were determined after the first running (0.49?0.05, in regard to
0.42?0.03 in resting phase), but 30 minutes after the second running there
was a slight drop of hematocrit values (0.46?0.04). The blood samples in
both cases were taken after fast trot during which there were recorded
maximal pulse values, so in the moment of sampling the pulse lowered close
to the values in resting - after the first running from 192.23?19.66, and
after the second from 180.33?17.22 to 40.67?5.76.