Response to selection with restrictions while considering effective family number

Area of Science:

• Quantitative Genetics
• Animal Breeding
• Statistical Genetics

Background:

• Genetic gain is crucial for livestock and crop improvement.
• Selection strategies impact the effective number of families contributing to the next generation.
• Balancing genetic gain with family diversity is a key challenge in breeding programs.

Purpose of the Study:

• To investigate the response to restricted selection based on effective family number.
• To analyze the trade-offs between genetic gain and effective family number under various restrictions.
• To compare different selection methods and their performance under restricted selection scenarios.

Main Methods:

• Numerical simulations were performed on large, normally distributed populations.
• Restrictions included maximum family limits and maximum individuals per family.
• Evaluated selection intensities, restriction intensities, and heritability effects.

Main Results:

• Restricted selection offers a practical approach to balance genetic gain and effective family number.
• Restricted phenotypic selection is advantageous when both high gain and a large effective family number are desired.
• Optimal-index selection without restrictions or with minimal restrictions maximizes genetic gain if a low effective family number is acceptable.

Conclusions:

• Selection strategies must consider the interplay between genetic gain and effective family number.
• Restricted selection provides a flexible tool for breeders to manage this trade-off.
• Findings were validated using real-world breeding data.