Mapping QTL for growth and muscling traits in three connected porcine F<sub>2</sub> crosses

Abstract

QTL experiments in pigs are often analysed separately, although similar or same founder breeds are frequently used to establish the experimental design. The aim of the present study was to jointly analyse three porcine F 2 -crosses for six growth and four muscling traits. The crosses were a Meishan × Pietrain cross, a Wild Boar × Pietrain cross, and a Wild Boar × Meishan cross. In some cases, same founder animals were used to establish the crosses. 966 F 2 -individuals were genotyped for 242 genetic markers (mostly microsatellites) and phenotyped for birth weight, 21 and 35 day weight, slaughter weight, carcass length, food conversion ratio, ham meat weight, shoulder meat weight, loin and neck meat weight, and meat area. A multi-allele multi-QTL model was applied that estimated an additive QTL effect for each founder breed and parental origin (either paternally or maternally derived), and a dominant QTL effect for each cross. This model was previously introduced in plant breeding. Numerous QTL were mapped on the autosomes. Most QTL were localised on SSC1, 2, 3, 4, 6 and 8, and no QTL were on SSC9, 11, 13, 15, 17 and 18. The confidence intervals were short in many cases. QTL with an exceptionally high test statistic were found for carcass length on SSC1, 4, 7 and 17. The coefficient of variation was remarkably small for this trait, which suggests that carcass length is affected by only a few genes with large effects. Positional and functional candidates underlying promising QTL are suggested for further study.

Genome‐wide association analysis for growth, muscularity and meat quality in Piétrain pigs

“…In recent studies, we conducted joint QTL analysis for growth and meat quality traits in pigs using three connected F2 crosses for which Piétrain was used as a founder breed (Rückert & Bennewitz ; Rückert et al . ; Stratz et al . ).…”