Neither does it improve the performance of dairy cows when used as a feed additive.
While biochar has been proposed as a potential solution for improving livestock health and reducing enteric methane emissions, peer-reviewed studies quantifying such effects in cattle are scarce and they report variable results, said the researchers, based at ETH Zurich and the Research Institute of Organic Agriculture FiBL, Switzerland.
They aimed to investigate the following hypotheses: that feeding biochar (BC) reduces enteric methane production, improves milk quality and nutrient digestibility, and enhances body condition and blood parameters related to animal health.
The Swiss experiment involved a 36-day crossover study on eight dairy cows, where the cows were fed their usual diet with and without 1% biochar.
Their study showed no significant impact from feed inclusion of BC on methane reduction, milk yield, nutrient digestibility, or animal health in healthy, high-performing cows fed a balanced diet.
Biochar’s role as feed additive remains unproven
The researchers suggest that while biochar might offer some benefits to ruminants facing health issues or poor nutrition, large-scale adoption of biochar as a feed additive in cattle farming may not justify the logistical and financial effort required.
Biochar is formed through the pyrolysis of plant material, creating a stable carbon compound that can act as a carbon sink when added to soils. Its use in agriculture, including co-composting and slurry amendments, has been explored for soil enhancement, but its role as a livestock feed additive remains unproven.
Although biochar could still be beneficial in soil improvement through manure, its efficacy in reducing methane emissions in cattle remains questionable, remarked the team.
Source: Animal Feed Science and Technology
Title: The effect biochar supplementation on feed utilization, milk production and methane emission in lactating dairy cows
Authors: MT Dittmann et al.