Effect of genetic stress susceptibility on pork meat quality
Project 18-004 - Lead Researcher - Dr. Ray Lu, University of Guelph
Pigs in production face all kinds of stress, including social stress (e.g., from feeding competition and aggression) and environmental stress (e.g., extreme temperatures, tight spaces and novel environments). It is well-established that stress affects an animal’s immune system and general health. In addition, stress also affects animal growth performance and the quality of meat for human consumption, and increases the likelihood of injuries and the overall cost of production. Sow stress is also linked to significant levels of piglet fatality via crushing or savage behaviours (Ringgenberg et al, 2012), which has a major economic impact on the industry.
In our recently completed pilot project, we found 8 single-nucleotide polymorphisms (SNPs) in the exon regions, 4 haplotypes and 9 genotypes, out of which 2 genotypes are associated high stress responsiveness and one is associated with low stress responsiveness (Larson, 2019). Based on these promising data, this project proposes to identify stress-related DNA markers that can be used to help reduce stress levels while maintaining a high level of meat quality through genetic breeding.
Objectives:
- Identify animals that have 150 highest and 150 lowest meat-quality;
- Amplify the DNA segments encompassing the Luman and LRF genes from DNA samples of the selected high and low meat-quality pigs and perform DNA sequencing to identify variations;
- Genetic association study of the DNA variations with meat quality parameters.
We genotyped over 100 animals for one SNP but the targeted genome sequencing was not successful after repeated attempts The DNA samples were used up and therefore could not complete the project as originally planned. Alternatively, the help of CCSI and researchers at the Department of Animal Bioscience at the University of Guelph, we developed a genetic evaluation system that can be used for genetic selection for sow’s overall performance, including piglet survival. The model can be further improved by the identification and inclusion of genetic markers to reduce sow stress and improve sow’s overall performance.
Our study results indicate that the genetic selection may be used to improve sow’s overall performance, including production efficiency and the welfare of pigs by reducing piglet losses.