Genetic parameters for semen traits in AI boars estimated from data on individual ejaculates

Area of Science:

• Animal breeding and genetics
• Reproductive biology
• Veterinary science

Background:

• Semen quality is crucial for artificial insemination (AI) success in boar populations.
• Understanding the genetic basis of sperm traits is essential for improving breeding efficiency.
• Previous studies have explored various factors influencing boar reproductive performance.

Purpose of the Study:

• To estimate genetic parameters for key semen traits in boars.
• To investigate genetic correlations between different sperm characteristics.
• To assess the feasibility of selection for improved semen quality using an animal model.

Main Methods:

• Analysis of 215,830 ejaculates from 3,675 boars across various breeds and crossbreds.
• Estimation of genetic parameters using multiple- and single-trait animal models.
• Inclusion of factors such as breed, age, collection interval, AI center, and genetic effects.

Main Results:

• Heritability estimates for semen volume and sperm concentration were around 0.20.
• Lower heritabilities were observed for motility, abnormal sperm percentage, and total sperm count.
• High negative genetic correlations were found between semen volume and sperm concentration (-0.68 to -0.69).
• Strong negative genetic correlations existed between motility and abnormal sperm percentage (-0.59 to -0.93).
• Repeatability estimates ranged from 0.29 to 0.50 for the studied traits.

Conclusions:

• Semen volume and sperm concentration exhibit moderate heritability, making them suitable targets for selection.
• Significant negative genetic correlations suggest potential trade-offs between volume and concentration.
• Effective selection for improved sperm characteristics, particularly volume and concentration, is achievable using an animal model approach.