THE ASSESSMENT OF GENETIC POTENTIAL IN PERFORMANCE TESTED GILTS BY MEANS OF SELECTION INDEXES METHOD

The objective of this research paper was to make an assessment of breeding value of performance tested gilts of Swedish Landrace and F-1 crossbreds of Swedish Landrace and Great Yorkshire by the method of selection index. The traits on whose basis the breeding value was estimated were: daily liveweight gain, average backfat thickness measured at two sites and carcass meat percentage. These traits were corrected for body mass of 100kg by the method of base indexes and the following average values were determined: corrected daily liveweight gain (KZDP) 408.93g/day, corrected average backfat thickness measured at two sites (KSL) 9.77mm and corrected carcass meat percentage (KPM) 61.08%. Studying the effect of genotype, year and birth season of gilts a statistically significant variation (P>0.05) of these traits provoked by the mentioned factors was not determined while the gilts sire statistically highly significantly (P<0.001) influenced all studied traits. Heritability coefficients were: h(2)= 0.255 for KZDP, h(2)= 0.356 for KSL and h(2)= 0.349 for KPM. The four selection index equations were constructed among which as the most optimal was chosen the one which includes all three traits (KZDP, KSL and KPM) and whose coefficient of the correlation of selection index and aggregate genotype was r(IAG) = 0.594.