Performance and Environmental Benefits from Biochar Supplementation in Beef Cattle Grazing Systems

Reducing greenhouse gas emissions from beef cattle production systems continues to be a pressing matter within the beef industry. The objectives of a series of experiments conducted were to: (1) determine the optimum dose of biochar for reducing methane emissions in beef cows.

(EXP1) and (2) determine whether biochar supplementation can reduce methane emissions from cows on pasture (EXP2). In EXP1, pregnant beef cows (n=8) of similar weight and stage of pregnancy were enrolled in a Latin square study with biochar (Oregon Biochar Solution, White City, OR) supplemented at 0, 1, 2, or 3% of total dry matter intake (DMI). Each period consisted of 21 d: 14 d adaptation and 7 d for data collection. Enteric gas emissions were measured using CLock GreenFeed trailers (C-Lock Inc., Rapid City, SD, USA) and DMI was measured using Insentec feeders (Insentec, Voorsterweg, The Netherlands). In EXP2, 64 cows were divided into 8 paddocks of 8 cow-calf pairs. Using a crossover design, each paddock was assigned to either control (no biochar) or biochar supplemented at 3% of estimated DMI. Enteric gas emissions from each paddock were measured as in EXP1 during the last week of each 4-week period. Pasture DMI was estimated using paddock entry/exit quadrats during each sampling week. Enteric methane emissions expressed in g CH4/day were not affected by biochar supplementation in EXP1 (P ≥ 0.56; although the 3% inclusion was numerically lowest) or EXP2 (P ≥ 0.37). Feed intakes (P ≥ 0.15) and cow weights (P ≥ 0.34) were also not affected by biochar supplementation in either experiment. Results suggest that biochar was not effective for reducing methane emissions from beef cows fed a forage diet or on pasture; however, animal performance was not affected. Further work is required to determine if type or higher inclusions of biochar can reduce methane emissions from grazing beef cattle.

Key words: biochar, methane, beef cattle, pasture.

Presented at the 2021 Animal Nutrition Conference of Canada. For information on the next edition, click here.