Biochar Benefits as a Feed Additive in Livestock Production

Biochar Benefits as a Feed Additive in Livestock Production

Remark: The references mentioned in square brackets [  ] relate to the references used in the scientific report of dr. Arnold on the Biochar Calculator. You will find these references under References. The text is an excerpt of the scientific report.

First of all, biochar offers considerable scientifically proven advantages as a feed additive. Numerous studies (see, e.g., reviews in [72 ][86][87][89][90], single study publications [91] to [116]) have shown that biochar reduces direct greenhouse gas emissions from livestock, especially cattle and swine, and improves yields in the breeding and husbandry of all livestock species. The economic benefits to the farmer are primarily in improved animal health, which is reducing the mortality rates, the required vegetarian cost, amounts and cost of pharmaceutics. Furthermore, and maybe this is the most important benefit from an agronomic viewpoint, biochar as feed additive is rewarded by increased weight gain rates of fed animals (swine, cattle and poultry) in some cases by improved meat quality. With respect to cattle, weight gain increases due to biochar as feed additive was reported [ 72 ] to be between +15% and +25% (in an extreme example even +60% [107]). For dairy cows it was reported [ 72 ] improvements of the milk quality due to biochar as feed additive (less contamination with aflatoxin, higher concentration of milk fat) could be observed. In some experiments even an increase of the specific daily milk production (increase by about 11% or 0.33 lbs./d) could be observed [ 115 ][ 116 ]. The reasons for these positive impacts of biochar as animal feed additive are multifold. Basically, the biochar with its extremely high specific surface area has selective adsorption qualities directed in particular to toxins like e.g., mycotoxins and dioxin. Moreover, biochar improves the electrochemical conditions in the gastroenteric system with their high redox activity. Biochar act like a battery as electron buffer and as electron mediator in biotic and abiotic redox-reactions. High temperature biochar (pyrolysis temperature > 600°C = 1112°F) is a good electrical conductor. The higher the pyrolysis temperature, the better is the electron transfer rate and the electrical conductivity of the material. The support of redox-reactions and increased conductivity facilitate the electron exchange between bacteria cells in the gastroenteric system, which in turn amplifies food conversion efficiency and strengthens the gastroenteric microbiome to cope with toxic and health burdening substances. A very detailed discussion of the electrochemical features and related biochemical processes in combination with biochar is presented in [ 72 ]. Apart from the related health benefits and improved production effects, the electrochemical features of biochar obviously also influence the enteric digestion processes, which produce methane emissions. This side effect of biochar as feed additive is decisive from a climate protection’s viewpoint. With focus on ruminants, there is sufficient empirical evidence that biochar as feed additive is significantly mitigating the enteric greenhouse gas emissions by about 22% (average of published values quoted in [ 72 ]). All of the positive impacts of biochar as feed additive, of course, imply that the biochar itself does not contain toxic or other ingredients harmful to health. This implies further that the biochar used as feed additive meets the requirements of relevant Feed-standards [ 56 ]. The cost of the required biochar can be outweighed by significant performance improvements and cost reductions as shown studies.

Biochar Benefits as an Additive to Stable Bedding

As an additive to stable bedding, biochar has a health- and thus yield-enhancing effect in the housing of cattle, pigs and poultry. The addition of biochar to the bedding improves the stable climate, reduces greenhouse gas emissions (especially ammonia, hydrogen sulfide and methane) and reduces the formation and spread of pathogens [ 117 ][ 118 ]. Livestock kept indoors occasionally ingest bedding material in their digestive tracts, the biochar used here must therefore meet the highest quality standards [ 56 ] (feed biochar). The benefit of mixing biochar into the stable bedding material works in two ways. The addition of biochar to the bedding material sanitizes it. At the same time, the bedding is charged with nutrients, colonized with beneficial microorganisms, and the reactive properties of the charcoal are increased. Thus, in addition to improving animal health and welfare, the stable can simultaneously be upgraded to a production site for Terra Preta substrates [117]. Depending on the soil composition, the biochar-containing stable manure produced in this way is considerably more valuable and yield-increasing than pure biochar or untreated stable manure when subsequently used as a fertilizer after incorporation into the soil (see also [73]).

Biochar Benefits as an Additive to Manure and Slurry

Furthermore, it has been proven that biochar also offers decisive advantages in the targeted pre-treatment of manure, slurry and other farm residuals of animal origin before application to agricultural land [ 73 ][ 86 ][ 117 ][ 118 ]. Pretreatment of the slurry with biochar prevents unpleasant odors in the slurry after a short time (about one hour after biochar addition, no more unpleasant odors are detectable15). Nutrients in the slurry are bound to the large adsorptive pore surfaces of the biochar, whereby nitrogen and phosphorus are stored more sustainably in the soil substrate like in an accumulator. This way nitrogen and phosphorus made available to plants in the long term and released to the root zone very gradually in contrast to the conventional way of distributing slurry and manure on the cropland surfaces, where precipitation may lead to fast elution. At the same time, emissions released into the air, soil and groundwater (greenhouse gases especially nitrous oxide and methane, fragrances, nitrates, salts, other constituents) from the organic fertilizer applied are reduced significantly [21 ]. Kebreab et al. (2021) concluded “Manure additives that include … biochar… significantly reduced CH4 emissions from manure…Biochar as a manure additive can be effective on compost manure (up to 82.4% reduction”… of CH4) [21]. The reduction of nutrient emissions is particularly important for groundwater protection: According to [ 73 ], a 30-day measurement of cumulative nitrate leaching showed 26% to 32% lower nitrate leaching when using biochar, and according to [ 74 ], NO3 leaching can be up to 60% lower, depending on the application conditions. In a scenario with a N-load limit to the cropland surfaces in order to constrain groundwater pollution with nitrates, the calculated area required for slurry application is considerably smaller with the use of biochar for nitrate immobilization than without. Biochar efficiently binds ammonium (NH4) and ammonia (NH3) as well as other odorous, often toxic substances due to an extremely high surface area. In experiments with pig slurry [120 ], for example, it was shown that pyrolysis biochar produced from wood and rice husks adsorbed 60% of the ammonium nitrogen (NH4+-N) found in the slurry. While in untreated slurry more than 30% of the nitrogen is lost during storage (to a significant extent via ammonia), treatment with biochar and lactic acid bacteria allows the majority of the nitrogen (according to the Ithaka Institute “almost all” nitrogen [ 119 ]) to be stored in a plant-available form. The effect of the biochar is crucial here for the nitrogen immobilization. A 2018 meta-study on changes in the nitrogen cycle found a mean increase in biological N fixation of +63% on legumes (cited in [ 73 ]). Depending on the soil conditions and the application method, fertilization efficiency can also be increased. Biochar can almost double the fertilization effect of slurry (liquid manure) in the most favorable application cases [ 119 ], according to the biochar experts at the Ithaka Institute. The leaching of slurry nutrients into the soil is significantly slowed, which not only protects groundwater but also prevents soil acidification. The biochar-treated slurry promotes soil activity and humus build-up (see, among others [ 73 ]).