The currently most promising possibility to use biochar in agriculture in an economically and ecologically beneficial way is by cascade use in animal husbandry. This is the conclusion reached by the authors Schmidt, Kammann and Gerlach in their book contribution for one of the scientific standard works on biochar (published by Quicker & Weber 2016, Biokohle, Springer Verlag). Biochar can be used as silage additive, animal feed, in litter, for manure treatment and as compost additive. The article not only gives a good overview of the different applications of biochar in animal husbandry, it also comprehensively summarizes the most important research results of recent years.
Effect of biochar in animal feeding
Before biochar was investigated and used as animal feed in the early 2000s, activated biochar was used as a veterinary medicine for digestive disorders and poisoning. Adsorption therapy (binding and accumulation of substances in the pores and on the surface of the biochar), in which biochar is used as a non-digestible carrier agent, is considered one of the most important methods to prevent harmful or lethal effects of orally absorbed toxins.
Another decisive function of biochar is its electro-biochemical interaction in biologically active systems. Biochar that was produced at temperatures of more than 550 °C is not only a good electrical conductor, but can also absorb and emit electrons in chemical and microbial redox reactions as electron mediators. It does not do this continuously, but its conductivity is based on discontinuous electron hopping. This electron hopping is indispensable for the microbial degradation of food in the digestive tract.
Effect of biochar on animal feed
Despite the many and varied properties of biochar, there are a number of central effects that have been observed during use in feed
- Increase in feed intake & increase in feed efficiency
- Increase in weight
- Strengthening of the immune system
- Improved meat quality
- Improved stable hygiene and reduced odour pollution
- Reduction of diseases and veterinary costs
Tests with cattle: The general state of health and vitality improved. The cell count of milk decreased significantly, milk protein and milk fat content increased. Hoof problems improved, diarrhoea symptoms decreased and faeces became firmer. The fertilising effect of the cattle manure increases.
Experiments with fattening pigs: The feed efficiency and thus the weight gain improved by almost 20%. The cortisol content was significantly lower, which indicates a lower susceptibility to stress. In addition, feeding with biochar resulted in the same growth increase as the standard amount of antibiotics used.
Experiments with poultry:Studies have shown that biochar can improve weight, feed efficiency and meat quality. Mortality decreased. There has also been an increase in egg production in poultry.
Requirements for biochar as feeding char
The binding and storage potential of plant coal depends in particular on the specific surface area and pore size distribution. According to the authors, activation of the biochar is generally not necessary, as the micropores produced are too small to absorb the substances relevant for animal digestion. The use of biochar in animal feed is regulated by the European Community Regulation (EC No 68/2013) and its quality requirements are laid down in EC No 178/2002. The European Biochar Certificate (EBC), a voluntary industry standard, guarantees compliance with all limit values prescribed by the EC regulation and also certifies sustainable production and use as well as other criteria relevant to biochar.
Author: Hans-Peter Schmidt, Claudia Kammann, Achim Gerlach, Henning Gerlach