Low Carbon Cows: Using Canola Meal to Reduce Livestock Methane Emissions

• Canola meal can increase milk and milk protein yield while increasing protein utilization.
• Canola meal as cattle feed can reduce methane output by up to 10%
• Increases in dietary fat concentrations can reduce enteric emissions.

Livestock produce significant amounts of methane as part of their normal digestive processes. Enteric CH4 emissions from ruminants represent a loss of dietary energy and contribute to greenhouse gas emissions. Depending on feeding level and diet composition, 2 to 12% of feed gross energy (GE) can be lost as CH4 ^2,4,8. Ruminant livestock (cattle, sheep, buffalo, goats) have a fore-stomach (or rumen) containing microbes called methanogens, capable of digesting coarse plant material producing methane as a by-product of digestion: this methane is released to the atmosphere by the animal belching. Ruminants are the principal source of livestock methane emissions because they produce the most methane per unit of feed consumed. Some feed additives can inhibit the microorganisms that produce methane in the rumen and subsequently reduce methane emissions¹⁴. The reduced volume of methane formation may lead to better efficiency of feed utilisation, given that methane emissions represent a gross energy loss from feed intake of about 10%¹⁴. Addition of fats and oils to the diet are a source of energy to the animal, as well as reducing methane. strategies that mitigate CH4 emissions are not only environmentally beneficial but can also result in greater efficiency of feed energy utilization by the animal⁴. Fertoz is working to help cattle and dairy operations produce low carbon cows using climate smart feed. The addition of canola meal to the feedstock can be an effective method of reducing livestock methane emissions.

The Research

Canola meal (CM) can be a cost-effective high-quality protein source and can be particularly beneficial for dairy diets⁷. The typical concentration of crude protein in canola meal varies from 38 to 42% of dry matter^3,5,11,12,13. Multiple studies have shown methane reduction from greater proportions of canola meal in cattle diets. Benchaar et al. 2021 concluded that replacing solvent-extracted soybean meal with canola meal in iso-nitrogenous diets of lactating dairy cows decreased enteric CH4 emissions expressed relative to gross energy intake by 13%. Nutrient intake, milk yield, and milk protein yield were increased by including canola meal in the diet, whereas milk fat yield was unaffected. Consequently, CH4 emission intensity (g/kg of Energy-corrected milk) declined by up to 10% at the greatest canola meal inclusion rate (23.7% of dietary dry matter)¹.

Moate et al., 2011 concluded that canola meal, when fed as feed supplements to lactating cows, reduced enteric CH4 emissions. Literature indicates that, regardless of type of fat supplementation, for each 10 g/kg DM increase in dietary fat concentration, enteric emissions are reduced by ∼0.79 g CH4/kg DM intake, or 3.5%. This inhibitory effect of fat supplementation on enteric CH4 emissions persisted for at least 7 weeks⁹. Using canola meal rather than soybean meal in the diet of lactating dairy cows can be a GHG mitigation strategy, lowering CO2e/kg FPCM depending upon where the CM is produced which affects its global warming potentia⁷. Gidland et al., 2015 found when compared to soybean meal, canola meal increased milk and milk protein yield, decreased MUN concentration, and improved protein utilization. Canola meal also resulted in a greater decrease in CH4 emissions per kilogram of ECM and it was concluded that soybean meal can be successfully replaced with canola in the diet of dairy cows fed grass-silage-based diets.

References:

1. Benchaar, C., Hassanat, F., Beauchemin, K.A., Gislon, G., and Ouellet, D. R. 2021. Diet supplementation with canola meal improves milk production, reduces enteric methane emissions, and shifts nitrogen excretion from urine to feces in dairy cows. J. Dairy Sci. 104:9645-9663 https://doi.org/10.3168/jds.2020-20053
2. Blaxter, K. L., and Clapperton, J.L. 1965. Prediction of the amount of methane produced by ruminants. Br. J. Nutr. 19:511-522.
3. Broderick, G. A., Colombini, S., Costa, S., Karsli, M.A., and Faciola, A.P. 2016. Chemical and ruminal in vitro evaluation of Canadian canola meals produced over 4 years. J. Dairy Sci. 99:7956-7970. https://doi.org/10.3168/jds.2016-11000.
4. Cabezas-Garcia, E. H., Krizsan, S.J., Shingfield, K.J., and Huhtanen, P. 2017. Between-cow variation in digestion and rumen fermentation variables associated with methane production. J. Dairy Sci. 100:4409-4424. https: / / doi .org/ 10 .3168/ jds .2016 -12206.
5. Gauthier, H., Swanepoel, N., and Robinson, P.H. 2019. Impacts of incremental substitution of soybean meal for canola meal in lactating dairy cow diets containing a constant base level of corn derived dried distillers' grains with solubles. Anim. Feed Sci. Technol. 252:51-63. https://doi.org/10.1016/j.anifeedsci.2019.04.007.
6. Gidlund, H., Hetta, M., Krizsan, S.J., Lemosquet, S., Huhtanen, P. 2015. Effects of soybean meal or canola meal on milk production and methane emissions in lactating dairy cows fed grass silage-based diets. J. Dairy Sci. 98:8093-8106 http://dx.doi.org/10.3168/jds.2015-9757
7. Holtshausen, L., Benchaar, C., Kröbel, R., Beauchemin, K.A. 2021. Canola Meal versus Soybean Meal as Protein Supplements in the Diets of Lactating Dairy Cows Affects the Greenhouse Gas Intensity of Milk. Animals, 11:1636. https:// doi.org/10.3390/ani11061636
8. Johnson, K. A., and Johnson, D. E. 1995. Methane emissions from cattle. J. Anim. Sci. 73:2483-2492.
9. Moate, P.J., Deighton, M.H., Williams, R.O., Pryce, J.E., Hayes, B.J., Jacobs, J.L., Eckard, R.J., Hannah, M.C., Wales, W.J. 2015. Reducing the carbon footprint of Australian milk production by mitigation of enteric methane emissions. Animal Production Science. http://dx.doi.org/10.1071/AN15222
10. Moate, P.J., Williams, S.R.O., Grainger, C., Hannah, M.C., Ponnampalam, E.N., Eckard, R.J. 2011. Influence of cold-pressed canola, brewers grains and hominy meal as dietary supplements suitable for reducing enteric methane emissions from lactating dairy cows. Animal Feed Science and Technology, Volumes 166-167:254-264. https://doi.org/10.1016/j.anifeedsci.2011.04.069
11. NRC (National Research Council). 2001 Nutrient Requirements for Dairy Cattle. 7th rev. ed. National Academies Press.
12. Paula, E. M., Broderick, G.A., and Faciola, A.P. 2020. Effects of replacing soybean meal with canola meal for lactating dairy cows fed 3 different ratios of alfalfa to corn silage. J. Dairy Sci. 103:1463- 1471. https://doi.org/10.3168/jds.2019-16947.
13. Sánchez-Duarte, J. I., Kalscheur, K. F., Casper, D. P., and García, A. D. 2019. Performance of dairy cows fed diets formulated at 2 starch concentrations with either canola meal or soybean meal as the protein supplement. J. Dairy Sci. 102:7970-7979. https://doi .org/10.3168/jds.2018-15760.
14. Agriculture and Food. 2022. Carbon farming: reducing methane emissions from cattle using feed additives. Department of Primary Industries and Regional Development. www.agric.wa.gov.au (accessed March, 2022). URL: https://www.agric.wa.gov.au/climate-change/carbon-farming-reducing-methane-emissions-cattle-using-feed-additives