Genetic influences on reproductive performance

Area of Science:

• Animal Science
• Genetics
• Reproductive Biology

Background:

• Genetic improvement in pigs offers substantial potential for enhancing reproductive performance.
• Current strategies involve utilizing F1 hybrid females and nucleus population selection.

Purpose of the Study:

• To evaluate the feasibility and methods for improving reproductive performance, specifically litter size, in pigs through genetic selection.
• To assess the economic importance of reproductive traits versus growth and carcass characteristics in breeding programs.

Main Methods:

• Focus on litter size as the primary selection objective due to economic, genetic, and measurement advantages.
• Utilizing artificial insemination to accelerate genetic gain and improve dissemination.
• Employing Best Linear Unbiased Prediction (BLUP) with data from genetically connected herds to incorporate relatives' information.
• Investigating indirect selection criteria, including testis size and molecular markers.

Main Results:

• Selection for litter size is challenging but not impossible, with some successful examples like the University of Nebraska experiment.
• Combining data and BLUP analysis allows for feasible selection for litter size while maintaining selection for growth and carcass traits.
• Research into prolific Chinese pig breeds aims to uncover the genetic basis of large litter size.

Conclusions:

• Genetic selection for improved reproductive performance, especially litter size, is a key goal in pig breeding.
• Advanced breeding techniques and data analysis make selection for litter size practical.
• Future research may focus on lifetime productivity and understanding the genetic underpinnings of prolificacy.