Genetic relationship between purebred and synthetic pigs for growth performance using single step method

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Livestock Breeding

Background:

• Understanding genetic correlations is crucial for effective breeding programs in synthetic pig populations.
• Synthetic breeds like WooriHeukDon have complex genetic origins, necessitating detailed genetic analysis.
• Previous studies have not fully elucidated the genetic architecture of growth performance in synthetic pigs.

Purpose of the Study:

• To estimate the genetic correlation (rpc) of growth performance traits between purebred (Duroc, Korean native) and synthetic (WooriHeukDon) pigs.
• To utilize a single-step method for accurate estimation of genetic parameters.
• To provide insights into the genetic basis of traits in synthetic pig breeds for future breeding strategies.

Main Methods:

• Utilized phenotypic data from 15,902 pigs and genotyped data from 1,792 pigs.
• Estimated genetic correlations for traits including day of target weight (DAY), backfat thickness (BF), feed conversion rate (FCR), and residual feed intake (RFI).
• Employed an animal multi-trait model with Bayesian inference to estimate variances and covariances.

Main Results:

• Genetic correlations within traits were low for DAY and BF, but high for FCR and RFI.
• A near-perfect genetic correlation (rpc ≈ 1) was observed for RFI between Duroc and WooriHeukDon pigs.
• Residual feed intake (RFI) in Duroc pigs showed associations with different traits in WooriHeukDon pigs, though many cross-trait correlations had high standard deviations.

Conclusions:

• Substantial differences in genetic correlations were found in synthetic WooriHeukDon pigs due to their complex origins.
• The strong correlation of RFI between Duroc and WooriHeukDon suggests shared genetic influences, potentially via single nucleotide polymorphism effects.
• Understanding these metabolic and genetic links is vital for developing new synthetic pig breeds with desired performance traits.