Genomewide association analysis for average birth interval and stillbirth in swine

Area of Science:

• Animal Genetics
• Reproductive Biology
• Quantitative Genetics

Background:

• Reproductive efficiency is crucial for economic success in pork production.
• Stillborn piglets and birth intervals significantly impact litter size and profitability.
• Understanding the genetic basis of these traits is essential for genetic improvement.

Purpose of the Study:

• To conduct a genomewide association study (GWAS) to identify genetic factors influencing piglet stillbirth and birth interval.
• To locate quantitative trait loci (QTL) associated with reproductive traits in pigs.
• To provide genetic markers for marker-assisted selection in commercial pig populations.

Main Methods:

• DNA samples from 798 first-parity sows were genotyped using the Illumina Porcine SNP60 BeadChip.
• Farrowing events were videotaped to record birth intervals and piglet status (stillborn or alive).
• Genomewide association analysis was performed using the Bayes C method with 1-Mb windows to identify significant SNP associations and QTL.

Main Results:

• Significant QTL were identified for the number of stillborn piglets (ignoring the last piglet) and stillbirth in the last birth position.
• Three significant QTL were detected for the percentage of stillborn piglets (ignoring the last piglet).
• Suggestive QTL were also identified for litter average birth interval and various stillbirth measures, indicating potential genetic influences.

Conclusions:

• The study identified significant QTL associated with stillbirth and birth interval traits in pigs.
• These findings offer potential genetic markers for marker-assisted selection and genomic selection strategies.
• Implementing these markers can aid in improving reproductive efficiency and economic outcomes in pork production.