College of Agriculture and Bioresources

Research Area(s)

  • Ruminant nutrition
  • Ruminal fermentation
  • Sustainable beef cattle production


Animal and Poultry Science

Other Affiliations/positions

Saskatchewan Beef Industry Chair

Research Interests

My research focus is on uncovering nutritional strategies to improve health, performance, and profitability, while simultaneously lessening the environmental impact of beef cattle production. This includes research focused on optimizing grain and forage processing technologies, consequently improving rumen health, feed efficiency, and beef cattle productivity. Other areas of interest are the development of nutritional strategies to reduce greenhouse gases emissions in beef cattle, and alternatives to the use of antibiotics as growth promoters. In vitro, in situ, and in vivo approaches are used in my research program to optimize beef cattle nutrition. The Rumen Simulation Technique (RUSITEC), a semi-continuous in vitro system, is often used in my research to investigate ruminal fermentation, digestion, and metabolism of different feedstuffs, additives, and/or toxins. Overall, my research goal is to identify technologies, and nutritional and management practices to improve the sustainability and productivity of forage-based and feedlot beef cattle production systems.


Post-Doctoral Fellow, Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada (AAFC), Lethbridge, AB, Canada

Ph.D. Animal Science/Ruminant Nutrition, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil with one year term at the Agriculture and Agri-Food Canada - Lethbridge, AB, Canada

M.Sc. Animal Science/ Ruminant Nutrition, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil

Veterinary Medicine (DVM), Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil

Selected Recent Publications

Terry, S. A., G. O. Ribeiro, R. J. Gruninger, A. V. Chaves, K. A. Beauchemin, E. Okine, T. A. McAllister. 2019. A pine enhanced biochar does not decrease enteric ch4 emissions, but alters the rumen microbiota. Frontiers in Veterinary Science, 6:308.

Gruninger, R. J., G. O. Ribeiro, A. Cameron, T. A. McAllister. 2019. Invited Review: Application of meta-omics to understand the dynamic nature of the rumen microbiome and how it responds to diet in ruminants. Animal (Cambridge) –

Ribeiro G. O., A. Badhan, J. Huang, K. A. Beauchemin, W. Yang, Y. Wang, A. Tsang, T. A.  McAllister. 2018. New recombinant fibrolytic enzymes for improved in vitro ruminal fiber degradability of barley straw. Journal of Animal Science, 96:3928–3942.           

Ribeiro, G. O., Oss, D. B., He, Z., Gruninger, R. J., Elekwachi, C., Forster, R. J., Yang, W., Beauchemin, K. A., and. McAllister, T. A. 2017. Repeated inoculation of cattle rumen with bison rumen contents alters the rumen microbiome and improves nitrogen digestibility in cattle. Scientific Reports. 7:1276.

Ribeiro, G. O., M. Huenerberg, D. Gibb and T. A. McAllister. 2017. Short-Communication: Impact of low- and medium-oil corn dried distillers’ grains plus solubles on growth performance of feedlot cattle. Canadian Journal of Animal Science, 97:530-535.


ANSC 802.3 - Advanced Animal Metabolism (graduate course)