EXAMINATION OF GENETIC-LINKAGE BETWEEN PUTATIVE QTL FOR MILK-PRODUCTION TRAITS AND MILK PROTEIN MARKERS USING MARKER ASSISTED COMPLEX SEGREGATION ANALYSIS

Marker assisted complex segregation analysis was applied to estimating the effects and position of a putative quantitative trait locus as well as polygenic parameters of five milk production traits and protein to fat ratio based on milk production performances of 1076 cows of Black Pied Dairy Cattle and Holstein Friesian as well as 645 cows of German Black and White. Genetic parameters including the recombination rate between marker locus and QTL were estimated by maximum likelihood method with the aid of the genetic marker information of polymorphic milk proteins: alpha(S1)-casein, beta-casein, kappa-casein and beta-lactoglobulin. No significant QTL effect was detected for the trait protein to fat ratio. Linkage between beta-casein and the QTL of milk and protein yield was found, however, the linkage was not significant due to the conservative test criterion. Majorgenic inheritance is not assumed according to the results.