The pork industry is a vital sector of Canadian economy, which exported $4.6 billion in 2017 (Canadian Pork Council, 2018), with Ontario being the biggest pork production province in Canada. There are 1,192 farmers who market 5.41 million hogs in the province (Ontario Pork, 2018). From the 300,000 breeding sows, 15 per cent of born piglets will not survive till weaning, 50 per cent of which (or 650,000 piglets) die from crushing or savage by the sows, resulting in ~$12.9 million loss to the Ontario pork industry each year. Animal stress and the related sow behaviours are believed to play a significant role in piglet survival and overall growth performance. A reduction of 10 per cent of piglet loss due to the stress-related crushing or attack from the sow (“savaging”) would bring about $1.3 million savings to Ontario pork industry annually; it would also represent an improvement in animal welfare which has become increasingly important for the growth and sustainability of the pork industry. Decades of production trait-driven genetic breeding may have been at the expense of other traits such as animal behaviours. In this proposal, we will validate our discovery of stress genes in pigs and identify beneficial genetic variations/DNA markers with the goal of lowering sow stress through breeding. With the help of our industry lead, Alliance Genetics Canada (one of the biggest breeding companies in Ontario), and our collaborator, Canadian Centre for Swine Improvement (which has broad connections with breeders and producers), we will make the lower stress DNA markers and/or breeding stocks available to other pig farmers in Ontario.