Objectives and strategies in pig improvement: an applied perspective

Area of Science:

• Animal Science
• Genetics
• Agricultural Biotechnology

Background:

• Simple performance testing has driven pig genetic improvement for 30 years.
• Modern swine production requires genetic objectives focused on both potential and its realization.
• Limitations in current genetic improvement strategies necessitate exploring advanced methodologies.

Purpose of the Study:

• To review advancements in pig genetic improvement strategies.
• To identify future directions for enhancing production traits and meat quality.
• To evaluate the potential of quantitative and molecular methods in swine breeding.

Main Methods:

• Review of established performance testing and genetic selection principles.
• Discussion of Best Linear Unbiased Prediction (BLUP) for increased accuracy and flexibility.
• Exploration of electronic feed intake measures and marker-assisted selection (MAS).

Main Results:

• BLUP methodology offers faster genetic improvement through enhanced accuracy.
• Electronic feed intake measures allow selection based on feeding behavior.
• Marker-assisted selection faces constraints from high DNA testing costs and small gene effects.
• A combination of BLUP, Meishan breed, and ESR gene may increase litter size by 4 piglets/litter in 10 years.
• Lean growth improvement seems unlimited, but risks include negative impacts on reproduction and disease resistance.

Conclusions:

• Quantitative genetic methods remain cost-effective for swine improvement.
• Molecular technologies face challenges, particularly in understanding the genetics of the immune system.
• Future genetic gains in pigs will likely involve integrating advanced quantitative and molecular approaches.