Eredmények: A C/C csoport mért izomvastagságai 22,08 (p =
0,004) és 12,24 (p < 0,001) %-kal; a cardiovascularis rendszeré 6,33 (p =
0,015), 6,03 (p = 0,011) és 6,72 (p = 0,014) %-kal magasabb volt, mint a T/T
genotípusnál. Pearson-féle R: anconeus pólyahossz r = 0,460; triceps r = 0,590;
aorta Valsalva-öböl diasztolé r = 0,423, szisztolé r = 0,450, billentyűk
síkjában szisztolé r = 0,462.
Következtetések: Az eredmények hozzájárulnak a galopplovak
hatékony tréningmódszereinek kidolgozásához, így jelentősen befolyásolható
Background: The myostatin gene (MSTN; g.66493737) C/T
polymorphism has great influence on the development of the muscles and the rates
between the types of muscle fibers as well as cardiovascular performance in
thoroughbred horses. Consequently MSTN gene decisively determines the optimal
race distance and racing ability in thoroughbreds through the muscle development
regulation. A more detailed understanding of these genetic attributions and
their associations leads us to be able to maximise the athletic potential of
Objective: In this paper the relationships were investigated
between the MSTN genotypes and muscle development or the main cardiovascular
parameters which affect or define the cardiac performance of thoroughbreds.
Methods: Ultrasonography and echocardiography was performed on
each individual selected for our study. Sixty-six thoroughbreds were applied in
each measurement (22 of each genotype, C/C, C/T and T/T). All of them
participated at different races or were trained at the same time in Hungary. A
portable MyLab™ ultrasound system (Alfa-Vet, Animal Healthcare Ltd.) was used
for the measurements. To investigate the development of the candidate muscles
the size of the anconaeous and triceps brachii muscles were used as indicators.
The length of the mentioned muscles was given by the size of the total length of
the muscle fascia (m. fasciae anconeus and m. fasciae triceps brachii).
Thickness was measured at the largest anatomical diameter of the muscles. To
characterize the cardiovascular system, the diameter of the Valsalva sinus of
the aorta was measured at the end of diastole and systole, respectively, as well
as the diameter of the aorta in the plane of the semilunar valves. The data were
analyzed with the SPSS 15.0 for Windows software. Homogeneity of variance
between groups was checked with Levene’s test and multivariate analysis of
variance was used to determine the correlations between the measured variables
and the myostatin genotypes.
Results According to our measurements relationship was detected
between individual myostatin genotypes, muscular development and cardiovascular
parameters of the thoroughbreds. The muscle thickness and fascicle length of
group C/C of MSTN showed significant differences compared to group T/T. Aortic
diameter at the sinus of Valsalva (end-diastole and end-systole) and aortic
diameter at the valve (end-systole) also indicated significant differences
between C/C and T/T genotypes too. The thickness of the two muscles (anconaeous
and triceps brachii) in the group C/C was 2.08 (p=0.004) and 12.24
(p<0.001) % higher; and of the parameters of cardiovascular system were
6.33 (p=0.015), 6.03 (p=0.011) and 6.72 (p=0.014) % greater, respectively, than
in the T/T genotypes.
Conclusions: The results contribute to a better understanding
of the effects of MSTN genetic variations on phenotypes, which help to develop
new, effective training methods for racehorses in order to prepare them for
their best race distance according to their genotypes. Thus, the competitive
performance and racing ability of thoroughbreds can be improved significantly.
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