RESEARCH CONCERNING THE VARIABILITY AND HERITABILITY OF THE CHIEF MORPHOLOGICAL TRAITS OF THE EQUINE POPULATION IN THE AREA OF THE PRAHOVA COUNTY
I. Dulugeac, V. Ujică
The heritability, as a characteristic of any measurable feature, is one of the most important indicators concerning the decisions to be made in the process of genetic improvement of the horse population. The studies and the researches undertook by several authors on the horse breeds in our country, although few in numbers and spaced in time, are marking a fairly large amplitude of characters and features inside each population, with the presence of individuals who's performances proving large capabilities of improvement regarding the corporal massivity as well as speed. The analysis of the heritability coefficients and of existing differences between coefficients' values, made by comparing the different studied subpopulations, are leading to the conclusion that the horse population in the area of Prahova county is formed of several structural biological units differentiated from one another by the genotype that forms them and that behaves differently as to the potentiality of the hereditary transmission of different morphological features. When the genetic variability is expressed in terms of heritability coefficient, it results that the highest values within the analysed populations were obtained for the following features: trunk oblique length (h2=0.43), thorax perimeter (h2=0.46), thorax width (h2=0.57), loin width at the hips' level (h2=0.39), cannon perimeter (h2=0.43), back length (h2=0.47), humerus length (h2=0.44), femur length (h2=0.47). The stronger determination of the hereditary variation for these features are evidentiating the reduced influence of the environmental factors and the high rate of genetic determination of the above mentioned features' variability. One can consider that the actions of genetic improvement within the analysed lots were carried on in the sense of hereditary fixation of characters that determine body massivity and enhancement of energetic capacity, that the higher genetic variability of this population insures a rapid effect of the selection and a higher probability of success in obtaining body massivity by selection.