Proposal for ‘occupancy rate’ of common ancestors, a new selection index to evaluate economical traits in animal genetic resources

Abstract

A new term, the occupancy rate (OR) of the ancestors of a breed, defined as the proportion of autosomal genomic information inherited from a common ancestor, has been proposed. The associations between the ORs of three paternal ancestors (Tajiri, Kedaka, and Fujiyoshi) of Japanese Black cattle (JBK) and carcass traits of the progeny of sire candidates were analyzed using data from the field progeny test conducted by the Livestock Improvement Association of Japan. The results suggest that further Kedaka OR accumulation will positively affect beef marbling score (BMS) and carcass weight (CW) and further Fujiyoshi OR accumulation will positively affect BMS. Thus, the optimal range that intersects the Fujiyoshi and Kedaka proportions produce the best CW and BMS. Moreover, further Tajiri OR accumulation negatively affects CW. Additionally, further Tajiri OR accumulation will positively affect BMS, but the effect is less than those of Kedaka and Fujiyoshi ORs. I conclude that the OR is a useful index for evaluating economic traits in animal genetic resources.

Keywords

• Genetic diversity
• selection index
• economical traits
• occupancy rate
• cattle
• breeding