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Assessment of methane emission traits in Canadian Holstein cows.

S. Kamalanathan




Assessment of methane emission traits in Canadian Holstein cows.
S. Kamalanathan*1, T. C. S. Chud1, D. Hailemariam2, P. Stothard2, G. Plastow2, F. Miglior1, C. F. Baes1,3, F. S. Schenkel1. 1Center for Genetic Improvement of Livestock, University of Guelph Guelph, ON, Canada, 2Department of Agricultural, Food and Nutritional Science, University of Alberta Edmonton, AB, Canada, 3Institute of Genetics, Vetsuisse Faculty, University of Bern Bern, Switzerland.

The reduction of greenhouse gas emissions has become an important area of research as Canada aims to reduce methane (CH4) emissions. This puts pressure on the Canadian dairy industry, as dairy cattle are responsible for roughly 13% of the total agricultural sector's CH4 emissions. In ruminants, CH4 is an output of the enteric fermentation produced by methanogens belonging to the archaea domain of microbes in the rumen. High enteric CH4 emissions of dairy cattle also cause a decrease in productivity due to a loss of gross energy intake. Breeding objectives should focus on improving the overall sustainability of dairy cattle by reducing CH4 emissions without negatively affecting economically important traits. The aim of this study is to determine the optimal methane trait for use in dairy cattle breeding and to investigate the genetic architecture of methane emission and its correlation with feed efficiency using Canadian data. A total of 2,451 daily CH4 production (grams/day) records from 335 Holstein cows were recorded from Canadian research herds located in Ontario (from 2017 to 2019) and Alberta (from 2015 to 2018) using GreenFeed stations (C-Lock Inc., Rapid City, South Dakota, USA). The overall mean and respective standard deviation (SD) of CH4 was 411.4 (116.6) g/d with a coefficient of variation of 28.3%. Higher mean of CH4 (476.3g/d) with a SD of 97.5 was observed for the Ontario herd compared with the Alberta herd (351.3 g/d) with an SD of 99.4. In contrast, the Alberta herd showed a higher coefficient of variation (28.3%) than the Ontario herd (20.5%). This result could be due to the differences in the number of times CH4 was collected in the herds. The need and alternative ways to standardize CH4 emissions between herds will be also investigated. The results of this study will help identify the most appropriate methane trait when monitoring/selecting for lower methane emissions in dairy cattle and will reveal the level of genetic correlation between methane emission and feed efficiency in Canadian Holstein cows.

Keywords: CH4, breeding, methane emission traits.

Biography: Stephanie is a M.Sc. student in the Centre for Genetic Improvement of Livestock under the supervision of Dr. Flavio Schenkel and Dr. Christine Baes at the University of Guelph. During her bachelor's, she was involved in studies conducted at the Elora Dairy Research Centre and worked at a commercial dairy barn which sparked interest in furthering her knowledge about the dairy industry and pursuing a master's in dairy cattle genetics. Her current research focuses on investigating the genetic architecture of methane emissions and the correlations between methane and feed efficiency to enable genetic improvement of these traits in dairy cattle.