Evaluation of the effects of biochar on diet digestibility and methane production from growing and finishing steers

Abstract

<jats:title>Abstract</jats:title> <jats:p>The objectives of these studies were to evaluate the effects of biochar (0%, 0.8%, or 3% of diet dry matter) on diet digestibility and methane and carbon dioxide production from cattle on growing and finishing diets. The growing diet consisted of 21% brome hay, 20% wheat straw, 30% corn silage, 22% wet distillers grains plus solubles, and 7% supplement. The finishing diet consisted of 53% dry-rolled corn, 15% corn silage, 25% wet distillers grains plus solubles, and 7% supplement. In both trials biochar replaced fine ground corn in the supplement. Six crossbred steers (initial body weight [BW] 529 kg; SD = 16 kg) were used in both the growing and finishing trial. The growing diets were evaluated over 6 periods followed by the finishing trial with 3 periods. Digestibility measures were taken over 4 d after at least 8 d of adaptation to diets followed by 2 d of gas emission measurements using headbox calorimeters. Dry matter intake (DMI) was not affected (P ≥ 0.43; 7.91 kg/d) by biochar inclusion in the growing study and increased quadratically (P = 0.07) in the finishing study with 0.8% biochar inclusion having the greatest DMI (12.9 kg/d). Organic matter (OM) and neutral detergent fiber (NDF) digestibility increased quadratically (P = 0.10) in the growing study whereas OM digestibility tended to linearly decrease (P = 0.13) and NDF digestibility was not affected (P ≥ 0.39) by biochar inclusion in the finishing diet. Digestible energy intake (Mcal/d) was not affected (P ≥ 0.25) by biochar inclusion in the growing or finishing study. Methane production (g/d) tended to decrease quadratically (P = 0.14) in the growing study and was decreased 10.7% for the 0.8% biochar treatment relative to the control. There were no statistical differences in methane production (g/d) in the finishing study (P ≥ 0.32) but cattle on the 0.8% biochar treatment produced numerically less (9.6%) methane than the control. Methane production as g/kg DMI of the 0.8% biochar treatment relative to the control was numerically reduced 9.5% and 18.4% in the growing and finishing studies, respectively (P ≥ 0.13). Carbon dioxide production (g/d and g/kg of intake) quadratically decreased (P ≤ 0.06) in the growing study but was not affected by treatment in the finishing study (P ≥ 0.34). Although biochar is not a U.S. Food and Drug Administration -approved feed for cattle, the initial research shows potential as a methane mitigation strategy in both growing and finishing diets.</jats:p>

A Pine Enhanced Biochar Does Not Decrease Enteric CH4 Emissions, but Alters the Rumen Microbiota

“…However, there were no associated benefits on apparent nutrient digestibility observed in the present study. This finding is consistent with Winders et al (10) who observed no changes in the total tract digestibility of steers fed either a high forage or high concentrate diet containing biochar at 3% of DM. Counter to this lack of effect, Van et al (38) found that digestibility of DM, OM, and CP were improved, and N retention increased in growing goats fed 0.5 and 1 g/kg BW of bamboo charcoal.…”

“…Although previous studies have found positive responses to a rice husk biochar (8), the present study utilized a pine EB due to its mass availability across the northern hemisphere. However, pine was the biomass used by both Saleem et al (1) and Winders et al (10) and the biochar still differed in surface area, bulk density and pH. These factors may affect the activity of EB within the rumen and subsequent metabolic responses in both the microbial population and the host animal.…”

“…However, a promotion in microbial biofilm development could also promote the growth of the archaea responsible for ruminal CH 4 production. Alternatively, Winders et al (10) found that biochar had no effect on intake, digestibility of nutrients, or CH 4 production in beef cattle.…”

The use of biochar in animal feeding

“…However, the enormously high addition of 9% cannot be considered as viable as this would surely impact feed digestibility on the long term. Winders et al (2019) did not detect any significant reductions on methane emissions in steers over a 23 h period when using the more realistic biochar supplement rates of 0.8% and 3%.…”

A Review of Biochar Properties and Their Utilization in Crop Agriculture and Livestock Production

“…Winders et al [61] evaluated the effects of a 0.8% and 3% BC diet inclusion for steers on growing and finishing diets. Digestibility, and CH 4 and CO 2 production from cattle were investigated.…”