The objective of this research was to identify genetic markers that would help predict first-parity reproductive and rebreeding performance. The goal is to improve the retention rate of gilts entering the breeding herd and their contribution to overall productivity.

Three commercial cooperators were identified and biological samples from 706 boars used in the industry were collected along with first-parity performance data of their daughters. In addition, data from 123 boars used at the U.S. Meat Animal Research Center were included in the study.

Performance data analyzed were number born alive, number born dead, total number born and wean-to-estrus interval. DNA was extracted from each boar and genotypic data was collected using the recently developed Illumina Porcine60K BeadChip. Genotypes were called for 59,895 single nucleotide polymorphism (SNP) markers spanning the entire porcine genome. Association analyses were performed to identify significant associations between SNP markers and performance traits.

In total, 14 different genomic regions were associated with a measure of reproductive performance. Two locations were associated with number born dead, nine locations were associated with number born alive, and two locations were associated with weaning-to-estrus interval. None of the regions appeared to be associated with measures of growth rate or backfat depth, so selection for improved reproductive performance would not be expected to result in poorer market hog performance. These results have the potential to improve first-parity reproductive performance in commercial herds.

Researcher: Gary Rohrer, U.S. Meat Animal Research Center, Clay Center, NE 68933. Contact Rohrer by e-mail Gary.rohrer@ars.usda.gov.