PSXIV-7 Performance and environmental benefits from biochar supplementation in beef cattle grazing systems

Abstract

Abstract Reducing greenhouse gas (GHG) emissions from beef cattle production systems has continuously been recognized as an important strategy to help mitigate climate change. This experiment was conducted to determine the optimum inclusion level of biochar (Oregon Biochar Solution, White City, OR) in the diet to reduce enteric methane (CH4) emissions from beef cows. Biochar is a stable form of carbon produced through low-oxygen and high-temperature pyrolysis of organic matter (typically forestry waste). Using a 4 x 4 Latin square design, pregnant beef cows (n = 8) of similar weight and stage of pregnancy were supplemented with biochar daily at 0, 1, 2, or 3% of total dry matter intake (DMI). Biochar was added to a pellet containing 45% biochar, 42.5% wheat midds, 10% canola oil, and 2.5% dry molasses to facilitate ease of feeding and encourage biochar consumption. Each 21-day period consisted of 14 days for diet adaptation and 7 days for data collection. Enteric gas emissions were measured using C-Lock GreenFeed trailers (C-Lock Inc., Rapid City, SD, USA) and DMI was collected using Insentec feeders (Insentec, Voorsterweg, The Netherlands). Enteric CH4 emissions expressed in g CH4/day, g CH4/kg DM, and g CH4/kg BW were not affected by biochar supplementation (P ≥ 0.41), although the 3% inclusion was numerically lowest. For all parameters expressing CH4 emissions, linear and quadratic effects for inclusion rate were not significant (P ≥ 0.19). Dry matter intake and cow body weights were not affected by biochar supplementation (P ≥ 0.34). These results suggest that biochar was ineffective for reducing CH4 emissions from beef cows fed a high forage diet (50% haylage, 30% straw, 17% corn silage) with no effects on animal performance. Further research should investigate whether type of biochar or higher inclusion levels of biochar can reduce CH4 emissions from beef cattle.