1. Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C&E Trail, Lacombe, Alberta, Canada T4L 1W1
2. Livestock Gentec, Edmonton, Alberta, Canada T6G 2C8
3. Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2P5
4. Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2