Genetic and biological architecture of pork quality, carcass, primal-cut and growth traits in Duroc pigs
Within the last few decades, swine
breeding programs have been refined to include pork quality and novel carcass
traits alongside growth, feed efficiency, and carcass leanness in the selection
programs for terminal sire lines with a goal to produce high quality and
efficient pork product for consumers. In order to accurately select for
multiple traits at once, it becomes imperative to explore their genetic and
biological architecture. The genetic architecture of traits can be explored
through the estimation of genetic parameters, genome-wide association studies
(GWAS), gene networks and metabolic pathways. An alternative approach to
explore the genetic and biological connection between traits is based on
principal component analysis (PCA), which generates novel “pseudo-phenotypes”
and biological types (biotypes). In this context, the main objective of this
thesis was to understand the genetic and biological relationship between three
growth, eight conventional carcass, 10 pork quality, and 18 novel carcass traits
included in two studies. The phenotypic data set included 2,583 records from
female Duroc pigs from a terminal sire line. The pedigree file contained
193,764 animals and the genotype file included 21,344 animals with 35,651
single nucleotide polymorphisms (SNPs). The results of the first study indicate
that genetic progress can be achieved for all 39 traits. In general, the heritability
estimates were moderate, while most genetic correlations were generally
moderate to high and favorable. Some antagonisms were observed but those
genetic correlations were low to moderate in nature. Thus, these relationships
can be considered when developing selection indexes. The second study showed
that there are strong links between traits through their principal components
(PCs). The main PCs identified are linked to biotypes related to growth, muscle
and fat deposition, pork color, and body composition. The PCs were also used as
pseudo-phenotypes in the GWAS analysis, which identified important candidate
genes and metabolic pathways linked to each biotype. All of this evidence links
valuable variables such as belly, color, marbling, and leanness traits. Our
findings greatly contribute to the optimization of genetic and genomic
selection for the inclusion of valuable and novel traits to improve productive
efficiency, novel carcass, and meat quality traits in terminal sire lines.
History
Degree Type
- Master of Science
Department
- Animal Sciences
Campus location
- West Lafayette