Italian heavy pig selection programs are based on production (average daily gain, ADG; feed gain ratio, FGR), carcass (weight of lean cuts, LC; ham weight, HW; backfat thickness, BFT) and meat quality traits of the green hams (ham weight loss at first salting, HWLFS; and visible intermuscular fat, VIF). In this study, we evaluated whether a selective genotyping approach previously designed for BFT could identify markers associated with other traits (ADG, FGR, HW, HWLFS, LC and VIF), most of which correlated with BFT. Italian Large White gilts were chosen according to their extreme estimated breeding values for BFT (275 with the most negative and 278 with the most positive EBVs) within a population of about 12,000 sib-tested pigs. A total of 736 single nucleotide polymorphisms (SNPs) in candidate genes for fat deposition and/or related traits were genotyped. After filtering, a total of 279 SNPs in 234 genes remained for association analyses that were carried out using random residuals (RRs) for the six mentioned traits. Four SNPs in three candidate genes were associated with some of the considered traits. A SNP in the exosome component 1 (EXOSC1) gene and a SNP in the glycogen phosphorylase L (PYGL) gene were associated with HWLFS RRs. Two SNPs within the TBC1 (tre-2/USP6, BUB2, cdc16) domain family, member 1 (TBC1D1) gene were associated with LC RRs and suggestively associated with other performance, carcass and meat traits. Association analysis using six TBC1D1 haplotypes, inferred from four genotyped SNPs within this gene, confirmed the results of the single-marker association study.

This study contributes to dissect the biological mechanisms underlying the genetic correlations among BFT, HWLFS and LC, which are critical for the sustainable implementation of tailored selection programs in heavy pigs.

意大利的重猪选择计划基于产量（平均日增重，平均日增重，饲料增重比，FGR），car体（瘦肉重量，LC，火腿重量，HW；后脂肪厚度，BFT）和绿色火腿的肉质特征（初次腌制时火腿减肥，HWLFS；可见的肌间脂肪，VIF）。在这项研究中，我们评估了先前为BFT设计的选择性基因分型方法是否可以识别与其他特征（ADG，FGR，HW，HWLFS，LC和VIF）相关的标记，其中大多数与BFT相关。选择意大利大型白种小母猪是根据其在大约12,000只经同胞测试的猪群中对BFT的极端估计繁殖值（其中EBV最阴性的275个，EBV最阳性的278个）。对脂肪沉积和/或相关性状的候选基因中总共736个单核苷酸多态性（SNP）进行了基因分型。过滤后，剩下的234个基因中总共有279个SNP用于关联分析，这些关联分析是使用随机残差（RR）对上述六个性状进行的。三个候选基因中的四个SNP与某些被认为的性状相关。外泌体组分1（糖原磷酸化酶L（PYGL）基因中的EXOSC1基因和SNP与HWLFS RR相关。TBC1（tre-2 / USP6，BUB2，cdc16）域家族中的两个SNP，成员1（TBC1D1）基因与LC RR相关，并暗示与其他性能，cas体和肉性状相关。从该基因内的四个基因型SNP推断出的六种TBC1D1单倍型的关联分析，证实了单标记关联研究的结果。

这项研究有助于剖析BFT，HWLFS和LC之间遗传相关性的生物学机制，这对于在重猪中可持续实施量身定制的选择计划至关重要。