Cattle taste testing feed with added biochar. Photo courtesy Adam Smith, the Nebraska Forest Service and the University of Nebraska-Lincoln.

Biochar for animal feed

By Justin Beck with Heather Nobert

A topic in biochar that ARTi has been interested in along with many others in the biochar field is the potential for the substance’s use in animal feed. The health of the animal products, the surrounding environment and the animal themselves has been demonstrated to have been positively affected by the addition to biochar to their feed. Furthermore, the potential for biochar’s addition to animal feed to reduce the impact of CO2 emission in animal farming shows exciting possibilities as well (Using biochar in animal farming to recycle nutrients and reduce greenhouse gas emissions, Hans-Peter Schmidt, Kelpie Wilson, and Claudia Kammann, Geophysical Research Abstracts Vol. 19,EGU General Assembly 2017) Link to conference paper.

In fact, the concept of making use of activated carbons as an additive to animal feed has been being researched for more than one hundred years. While often unclear, the distinction between biochar and activated carbon according to Achim Gerlach & Hans-Peter Schmidt in 2014 article in the Biochar Journal titled The Use of Biochar in Cattle Farming states that “all activated carbons are originally biochars. Active carbons are however “activated” using acids or hydroxides or 900°C water steam. In doing so, their specific surface area increases from app. 300 m2/g to over 1000 m2/g.”. The use of biochar for animal feed is less expensive than activated carbon even if it requires a larger amount. Nevertheless, the potential for biochar in animal feed seeks to address several key concerns and varies to some degree between the types of livestock being fed.

According to Gerlach & Schmidt who quote a test performed by the Central Laboratory of German Pharmacists who compared commercially available activated charcoal with biochar found that cattle fed with biochar treated feed showed a number of positive outcomes which included:

• Generally improved health and appearance

• Improved vitality

• Improved udder health

• Decreased cell counts in the milk (interrupting the administration of biochar leads to higher cell counts and a drop in performance)

• Minimization of hoof problems

• Stabilization of post-partum health

• Reduced diarrhea within 1-2 days, feces subsequently generally became more solid

• Decline in the mortality rate

• Increase in milk protein and/or fat

• Combining biochar and sauerkraut brine has proved worthwhile

• Marked improvement of slurry viscosity, with less stirring needed and less scum on the surface

• Slurry not smelling as bad as it used to

Preliminary tests on the slurry show that adding biochar via the gastrointestinal tract or via direct application:

• Increased ammonium nitrogen in slurry

• Reduced nitrate

Gerlach & Schmidt go on to list several trials examining the effects of biochar in the feed for a number of other livestock types.

“From an international perspective, we are currently seeing repeated reports on the advantages of mixing biochar into animal feed:

• It’s used with goats in North Vietnam. Growth rates improved here when feed included 0.5-1g of bamboo charcoal / kg per day (DoThiThanVan, 2006).

• Kana et al. (2011) have shown that 0.2-0.6% corncob charcoal added to chicken feed results in significant weight increases. Number better 5% eg.g

• Leng et al. (2012) proved that methane formation could be reduced by 12.7% (10%) when 1% (0.5%) char is added to an artificial rumen system.

In the case of CO2 reduction, Schmidt et al conclude that, “Considering an average C-content of fed biochar of 80% and produced at recommended temperatures above 500◦C resulting in H/Corg ratios below 0.4, at least 56% of the dry weight of the fed and manure-applied biochar would persist as stable carbon in soil for at least 100 years. If the global livestock would receive 1% of their feed in form of such a biochar, a total of about 400 Mt of CO2eq or 1.2 % of the global CO2 emissions could be compensated. The apparent potential for improving animal health and nutrient efficiency, for reducing enteric methane emissions as well as GHG emissions from manure management and for sequestering carbon with soil fertility improvements makes it compelling to increase the scientific effort to investigate, measure and optimize the GHG reduction potential of biochar use in animal farming systems.”

A more recent paper, The use of biochar in animal feeding by Hans-Peter Schmidt, Nikolas Hagemann, Kathleen Draper and Claudia Kammann looked at 112 scientific publications that addressed biochar’s use in animal feed in an effort to sum up the state understanding of this topic up to 2019. Their paper offered several paths where further research is needed. Firstly, a complete understanding of how biochar’s application to animal feed causes its effects on animals needs to be further addressed. Secondly, the authors found that an analysis of different types of biochars and their feedstocks of origin was lacking in the literature. This second point leads to the third point the authors make which is the question of which types of animal feeds are best with which types of biochars in terms of any effort to optimize any positive effects or minimize any potential negative ones. Additionally, Kathleen Draper has reminded us that biochar for use with animal feed is not yet legally approved in the US and that this fact must be highlighted. This added point further supports the need for more research.

Heather Nobert has informed ARTi about two biochar feeding trials projects completed by the University of Nebraska-Lincoln. The first, which produced the paper Evaluation of the effects of biochar on diet digestibility and methane production from growing and finishing steers by Thomas M. Winders et.al. was 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.” Pine derived feedstock used was for the biochar. Six crossbred steers were used for the experiment. Several of the findings for these trials indicated that biochar enhanced feed improved daily grain and feed efficiency and even more promising did demonstrate a marked reduction in both methane and carbon emissions from the cattle.

A second project directed by University of Nebraska-Lincoln Department of Animal Science students Tim Winders and Melissa Jolly et. al. was titled Biochar as a Cattle Feed Supplement. Possible reductions of greenhouse gases, in particular methane, was the principal focus. Similar to the previous trials, there was a perceivable improvement in feed efficiency and a 16% reduction in methane production by the cattle.

A new, more expansive feed trial that Heather Nobert is involved in with the University of Nebraska-Lincoln through the USFS Wood Innovations Program is in the works. The deliverables for this grant include:

• Characterize biochars based on existing industry standards to determine their potential as a cattle feed additive.

• Determine the effects of feeding biochar on cattle performance on methane emissions, feed intake, and daily gains in both growing and finishing diets

• Assess the economics of mobile and stationary biochar production systems using Nebraska feedstocks (mainly ponderosa pine and eastern redcedar, but also mixed hardwoods to a lesser extent).

According to the trial proposal abstract, the study “will evaluate the effects of biochar on cattle performance and impacts on methane production using the pen scale methane barn.”

One exciting possibility for the trial would be to determine if biochar used in cattle feed could reliably reduce “methane emissions from each cow in Nebraska by 10% (which) would be equivalent to removing 150,000 cars from the road for 1 year or installing 182 wind turbines.” At ARTi we are, of course quite interested in finding out more about the results and progress of this trial as it nears completion next year. Lastly, we applaud Heather Norbert, the Nebraska Forest Service and the University of Nebraska-Lincoln for their contribution to the scientific knowledge of biochar and the promotion of its use in the context of animal feed.

Link to the article The use of biochar in animal feeding by Hans-Peter Schmidt, Nikolas Hagemann, Kathleen Draper and Claudia Kammann.