The use of biochar in animal husbandry continues to be a key source of interest among researchers and its application is signalling at an effective, non-invasive and low-cost strategy that could markedly improve the sustainability and outcomes of animal husbandry and farming more generally.
This is a topic which the Green Man's Blog first touched on back in 2018 (see link to previous post), however, expanding research continues to shed light on the various intricate mechanisms by which biochar interacts with gastrointestinal and broader metabolic processes in livestock and their products, and the real-world environmental and economic implications of biochar used in animal husbandry more broadly.
Schmidt et al. (2019) published an excellent and extensive review covering the current state of published research on the topic. The highlights of this review along with other landmark research on the subject will be the topic of a series of upcoming blog posts as the topic and state of knowledge is too vast to cover in one post. For this week’s post, the Green Man’s Blog will take a closer look at biochar as an animal feed additive and cover some of the highlights from the review paper by Schmidt et al. (2019). But first, some background...
The use of biochar in animal husbandry is a common practice
The use of biochar in animal husbandry is in common use and there is evidence that the application of biochar as an animal feed additive and curative has occurred for millennia. In the case of modern management techniques, biochar is increasingly being adopted in animal husbandry as it gains recognition for a range of on and off farm benefits, particularly in Europe and Australia. Currently in Europe, the largest end-use of industrially produced biochar is as an additive in feed, bedding and manure treatment (Schmidt et al., 2019).
Biochar as a feed additive
As a feed additive, biochar is shown to increase nutrient uptake and improve the overall feed efficiency and the feed to weight ratio for livestock. Further, biochar helps control gastrointestinal pathogens and reduces methane emissions from livestock.
Schmidt et al. (2019) provides and overview of the results of 27 individual peer-reviewed studies investigating biochar as an animal feed additive ranging from feed for cattle, poultry, goat, sheep, pig and aquaculture with feed rates ranging from 0.2-4% (weight) of livestock basal diet. This week’s post will focus on studies feeding biochar to cattle.
Biochar as a feed supplement for cattle
In cattle, biochar in feed was reported—by surveyed farmers using the practice—to improve the overall health and vitality of animals. Harmful bacteria measured in the milk (as the somatic cell count) of biochar fed cattle was indicated to decrease significantly. Farmers also reported a decrease in hoof problems, greater postpartum health, reduced symptoms of diarrhoea, an overall decline in mortality rates and a decrease in associated veterinary costs (Schmidt et al., 2019; study from Gerlach and Schmidt, 2012).
Biochar was shown to increase live weight and feed efficiency in cattle fed at a rate of 1% by weight of basal diet, with one trial indicating a 31% increase in feed conversion rate using biochar as a feed additive alone, and a 60% increase in feed conversion rate when biochar was enriched with a rice wine distillery (fermented) byproduct. This compares to an 18% increase in feed conversion rate when animals were fed the fermented wine byproduct alone (Schmidt et al., 2019, study from Phongphanith and Preston, 2018).
The above findings indicate that even relatively small supplementation of biochar can result in disproportionately enhanced growth benefits. Additionally, by combining biochar into diets with other beneficial feed additives enhances the outcomes of both amendments.
Stay tuned for future blog posts in the upcoming weeks that will cover other livestock groups and delve deeper into ways biochar can be used to improve livestock health and productivity.
Further reading:
For further reading and links to individual studies, see the full review paper and references by Schmidt et al. (2019):
Schmidt, H.P., Hagemann, N., Draper, K. and Kammann, C., 2019. The use of biochar in animal feeding. PeerJ, 7, p.e7373.
Studies covered:
Gerlach A, Schmidt HP. 2012. Pflanzenkohle in der Rinderhaltung (translated as “Biochar in cattle farming”). Ithaka Journal1:80-84, English translated version access via: http://www.ithaka-journal.net/pflanzenkohle-in-der-rinderhaltung?lang=en.
Phongphanith S, Preston TR. 2018. Effect of rice-wine distillers’ byproduct and biochar on growth performance and methane emissions in local “Yellow” cattle fed ensiled cassava root, urea, cassava foliage and rice straw. Livestock Research for Rural Development 28:Article #178.