Directly linked to this problematic situation is the appearance of chronic botulism that reached disturbing levels in herds of cattle over the last few years (Krüger et al. 2012, Böhnel u. Gessler 2012). Affecting cattle, the disease – a toxic infection – is caused by clostridium botulinum toxins and is leading to significant direct and indirect losses in livestock farming. In her search for the main factor(s) influencing the emergence of this new phenotype, Krüger (2012) took a close look at the role played by glyphosate, a broad-spectrum systemic herbicide, and AMPA, its main metabolite. Her research revealed major amounts of glyphosate notably in the urine of dairy cows (up to 164 micrograms / l in Germany and up to 138 micrograms / l in Denmark, on average 20-50 micrograms / l) but also in rumen fluid (0.04 to 122 micrograms / l). Glyphosate was also found in human urine (up to 2.8 micrograms / l), although to a much lesser degree (see: Herbicides found in Humane Urine). Moreover glyphosate has also been detected in digestate from biogas plants and in different animal feeds, often in alarming concentrations. The fact that glyphosate has antibiotic effects is incidentally well-known to the producers of the herbicide, with Monsanto even filing an application for it to be patented as such (US-Patent 7,771,736, EP0001017636). When glyphosate gets into the digestive tract of animals and humans, it causes detectable changes in the gastrointestinal microbiota.
A good prophylactic, metaphylactic and therapeutic possibility of binding botulinum toxin and other toxins formed by clostridia, as well as the herbicide glyphosate increasingly detected in feedstuff, in the gastrointestinal tract of cattle seems to be the administration of biochar.
The effect of activated carbon and biochar in feeding
For some hundred years, research into activated carbon has been showing effective ways of adsorbing pathogenic clostridial toxins such as C. tetani und C. botulinum (Kranich 1920, Luder 1947, Starkenstein 1915). Wang et al (2010) have shown that biochar has good sorption qualities with regard to the hydrophobic herbicide terbuthylazine and underline the important role it can play in protecting ground water. Graber et al. (2011) studied the binding qualities of the model herbicides S-Metolachlor and Sulfentraton on biochars with different surface sizes. Graber (2012) confirmed that biochar can adsorb glyphosate. The use of carbon gained from pyrolysis for feeding purposes has been known for a long time and is recommended in Germany. Mangold (1936) presented a comprehensive study on the effects of charcoal in feeding animals, concluding that "the prophylactic and therapeutic effect of charcoal against diarrhoeal symptoms attributable to infections or the type of feeding is known. In this sense, adding charcoal to the feed of young animals would seem a good preventive measure."
Activated carbon = biochar?
Generally speaking, 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. Activated carbon is 5 – 10 times more expensive than simple biochar, so it is possible to use 2-3 times the amount of biochar to achieve the same result – whether with regard to digestion in cattle or in a sewage treatment plant. As activated carbon is for the most part produced without adequate controls in South-East Asia or South America, the eco-balance often leaves a lot to be desired. Biochar by contrast is produced from controlled, locally grown raw materials using controlled production methods. There is no real difficulty involved in producing activated carbon from biochar.
Volkmann (1935) describes an efficient reduction in excreted oocysts through adding charcoal to the food of pets with coccidiosis or coccidial infections.
Haring (1937) recommends mixing charcoal into cattle feed, while Barth and Zucker (1955) were not able to establish any negative growth effects in poultry when the level of added charcoal was kept at around 1%.
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 coal / 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.
• Iwase et al. (1990) have demonstrated – in an experimental environment – the storage effect of activated carbon in rumen acidosis in Holstein bulls.
• 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.
The effects of biochar are based on the following mechanisms: adsorption, coadsorption, competition, chemisorption, adsorption followed by a chemical reaction, desorption. From a toxicology perspective, classifiable distinctions need to be made to the time-dependent processes of adsorption, distribution, biotransformation and excretion of the toxic substances in the digestive tract of animals.
With regard to the specific mechanisms, more detailed research is urgently needed.
Schirrmann (1984) describes the effect of activated carbon on bacteria and their toxins in the gastrointestinal tract:
1. Adsorption of proteins, amines, amino-acids
2. Adsorption of digestive tract enzymes, as well as concentration of bacterial exoenzymes in the activated carbon
3. Adsorption, via chemotaxis, of mobile germs disposing of special attachment mechanisms.
Of particular importance is the specific colonisation of the char with gram-negative germs with increased metabolic activity. This results on the one hand in a decrease in endotoxins needing to be resorbed and on the other hand in the adsorption of the toxins in the char.
Ariens and Lambrecht (1985) describe the advantages of activated carbon, stating that it is non-toxic, quickly available, has an unlimited shelf-life, is effective in the gastrointestinal tract, and is effective against already absorbed toxins and mineral oil products.
One major advantage in the use of biochar is to be found in its “enteral dialysis” property, i.e. already absorbed lipophilic toxins can be removed from blood plasma by the char, as the adsorption power of the huge surface area of char interacts with the beneficial permeability properties of the intestine. Adsorption applies to both lipophilic and hydrophilic substances. The speed at which adsorption takes place is dependent on the size of the activated carbon’s pores. What we are thus seeing is the emergence of a genuine alternative to the established medical therapies – peritoneal dialysis, haemodialysis or haemoperfusion.
Via manure and slurry, the biochar mixed with the feed is returned to the soil, closing the organic cycle. The fact that biochar returned to the soil this way can be of interest for agriculture was already described by Perotti back in 1935. For him, the presence of biochar in the soil meant an improvement in its microbiological properties and a better supply of chlorophyll for the plants.
In his view, the benefits of biochar were as follows:
1. Moisture retention
2. Increased adsorption of ammonium salts
3. Decreased dispersion of nitrates
4. Adsorption of microbial metabolites
Söhngen (1913) sees the formation of ammonium carbonate combined with the char adsorption as playing a key role in the longer-term development of rich cultures of bacteria which find their way into their surroundings through desorption. In a slightly acidic environment in particular, this process of alkalization through the adsorption of carbon only takes place slowly. Schirrmann (1984) reports that the oxidisation reactions on activated carbon can be improved through increasing the nitrogen content. Nagel (1990) studied activated carbon populated by bacteria, without being able to find any efficient method of desorbing adherent bacteria. Proving the existence of bacteria via excreted metabolites was not possible, and the only way of determining adherent cell counts was through the use of a gamma-ray marker (Fe-59).
The use of biochar in cattle farming
Biochar was administered at a dosage of 200-400g per cow and day in the farms I myself am responsible for, on the basis of studies by Feldmann (1992), who conducted in vitro experiments with activated carbon. But the adsorption capabilities of chars gained by pyrolysis show major variations. Chars produced from wood and plants are unable to exceed the level of the so-called “blood carbon” which contains a further adsorbent, bentonite, and is activated at higher temperatures. Feldmann (1992) studied the effects of activated carbon on fermentation processes in rumen fluid (in vitro), detecting an up to 25% increase in the pH-level, an up to 32% decrease in the redox potential, a reduction in the concentration of volatile fatty acids (though the production rate remained constant), and a rising adsorption rate with increasing chain lengths of the volatile fatty acids. These effects were dependent on the char dosage.
The use of biochar as a feed ingredient is subject to strict food quality rules under EC Regulation 178/2002 and to the strict regulations for organic livestock feed under EC Regulation 834/2007. In particular, the levels of heavy metals, dibenzodioxins and dibenzofurans play an important role as limiting factors, whereby biochar produced under the European Biochar Certificate meets all the animal feed threshold values. In our own tests, the only biochar used was inert biochar (carbo ligni) made by means of a technical pyrolysis using the so-called “Schottdorf reactor”. The safety of biochar as a feed additive has been certified by Biocheck, a laboratory for veterinary diagnostics and environmental hygiene. Preliminary tests on the adsorption capacity of the biochar used were performed by the Central Laboratory of German Pharmacists, comparing it with commercially available activated medical charcoal using the phenazone adsorption test. The adsorption capacity of 16.7 g phenazone/100g dried biochar is about one-third of the levels reached by medical charcoals of 40g phenazone/100g charcoal. These results confirm the findings of Luder, W. (1947), who studied the adsorption capacity of carbo ligni and carbo adsorbens and came up with a ratio of 1:3-4.
Now that biochar can be produced economically (i.e. it is available at low cost and high quality), the long-known benefits of feeding biochar can be feasibly put into practice.
Practical use of biochar in feeding cattle
21 farm managers, each with an average herd of 150 cows, gave their impressions of the effects they had observed during and after the administration of biochar. It should be noted that biochar administered as treatment for dysbiosis was concomitantly supported in about 1/3 of the farms by sauerkraut brine (acetylcholine, lactobacilli, enterococci, B-vitamins, vitamin C).
Observations of initial effects (1 – 4 weeks after starting biochar administration):
• 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)
• Minimisation of hoof problems
• Stabilisation of post-partum health
• Reduced diarrhoea within 1-2 days, faeces subsequently generally 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
• Reduced nitrate and nitrite
Summary and conclusions
The use of biochar in livestock farming offers solutions to the increasingly complex problems of modern-day farming, the result of a combination of profit maximisation and disrespect for the physiological needs of the animals. The adsorption qualities of biochar permit a wide range of toxic substances to be bound in the gastrointestinal tract. They also lead to the detoxification of already resorbed toxins (in particular lipophilic toxins) in the plasma via “enteral dialysis”. The oxidation and deamination of biogenic amines also play a particularly stabilising role in the intestines. Dysbiosis can be very efficiently and positively influenced by biochar, and eubiosis can be maintained much longer despite environmental fluctuations in the digestive tract.
A clear separation of the impact in the pro- or metaphylactic field and the therapeutic approach is desirable in theory, though in practice these effects are overlapping. In cases of acute intoxication, the parallel administration of saline laxatives is recommended (Wiechowski 1914).
One current problem affecting Schleswig-Holstein and Lower Saxony in particular is the high level of nitrate pollution in drinking water, the result of intensive farming. The scientific methods for reducing nitrates in the soil have been known for more than a century. Reductions can be achieved by the intelligent use of commercial fertilisers based on biochar. Reports in this area have been published by Sommer (2005). Similarly, the changed economic conditions under which farms operate mean that what is now needed is a re-assessment of certain practices from an epidemiological perspective. These include the disposal of placentas via the slurry system and the widespread use of bone meal as a fertiliser especially on account of increased maize production. One option available for minimising expected epidemiological and drinking water problems involves the inclusion of inert biochar in agricultural cycles of organic matter.
Also necessary are tests on the biochar used, making sure that it complies with the structural, chemical, physical and biological requirements of the European Biochar Certificate (EBC). This is the only way to achieve a transferability of the results gained in the use of different chars to other studies.
Achim Gerlach is a vet working for the Schleswig Holsteinschen Landkreis Dithmarschen and is probably the expert with the most experience in Europe on the administration of biochar in livestock feed. Should readers wish to directly contact the author, please just drop us a line.
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