Optimal utilization of non-additive quantitative trait locus in animal breeding programs

Area of Science:

• Quantitative genetics
• Animal breeding
• Genomic selection

Background:

• Optimal selection strategies are crucial for maximizing genetic gains in breeding programs.
• Understanding the influence of quantitative trait locus (QTL) inheritance modes and breeding structures on selection effectiveness is essential.

Purpose of the Study:

• To evaluate the extra benefit of mate selection over index selection for a single identified QTL.
• To compare the effectiveness of mate selection across four inheritance modes (autosomal, sex-limited, imprinting, X-linked) and four breeding structures (SLS, 2WC, 3WC, RC).

Main Methods:

• Simulation study evaluating optimal selection on a single QTL.
• Comparison of mate selection versus index selection.
• Analysis across varying inheritance modes, allele frequencies, and breeding structures.

Main Results:

• Mate selection superiority varied significantly based on QTL inheritance mode, allele frequency, and breeding structure.
• Imprinted QTLs showed high superiority (6.41-41.54%) with mate selection, particularly maternal imprinting.
• Over-dominant QTLs also demonstrated substantial superiority (up to 27.11%) compared to recessive or fully dominant QTLs.

Conclusions:

• Mate selection is highly effective in exploiting non-additive QTL effects, especially for imprinted and over-dominant loci.
• Breeding structure significantly impacts the advantage of mate selection, with 3WC and 2WC often showing greater benefits.
• The findings provide valuable insights for optimizing selection strategies in animal and plant breeding programs.