[Association of parameters of crossbreeding effect for traits of growth and meat-production with average band-sharing of RAPD markers in commercial crosses of Duroc, Landrace and large white pigs].
Parameters of crossbreeding effect have been estimated for average daily gain (ADG), dressing percentage (DRP), backfat thickness (BFT), percent of hind legs (HLP), and average band-sharing of RAPD markers, by using individual records of growth and meatproduction and genotypes of RAPD analysis in crosses of Duroc, Landrace and Large White pigs from 1996 through 1998. The results indicate that significant individual and maternal genetic effects exist for all the 4 traits of growth and meat-production (P < 0.05). Effects of individual heterosis and maternal heterosis have also been found to be significant for ADG (P < 0.05), but not significant for DRP, BFT, and HLP (P > 0.05). Maternal genetic effect is positive and the effects of individual heterosis and maternal heterosis are negative for RAPD-marker ABS. Correlation analysis reveals that the total correlation, which includes all parameters at a time, is low and not significant. The partial correlation, however, is more reasonable than total correlation, which consider 1 parameter each time, or 2 in case of heterosis. All 3 partial correlations between ADG and RAPD-marker ABS are significantly greater or smaller than zero (P < 0.05), among which the correlation for individual genetic effect is very significant (P < 0.01). It is therefore concluded that the efficiency of predicting heterosis is low by simply applying total correlation. Alternatively, estimation of parameters of crossbreeding effect for both economic traits and DNA markers provides a way of efficiently predicting heterosis for it dramatically increases the correlation between markers and traits of economical importance. Increasing QTL coverage (percent of markers linked to QTL) will as well contribute to improved accuracy of predicting heterosis. It is also implied from the partial correlations that, while genomic similarity of crosses increases, individual genetic effect would increase, but that of individual heterosis and maternal heterosis would decreases.
Shi
Q S
QS
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.
Liu
X C
XC
Wu
X L
XL
D000818:Animals; D001947:Breeding; D003433:Crosses, Genetic; D006128:Growth; D019105:Random Amplified Polymorphic DNA Technique; D013552:Swine / Q000235:genetics*