Interpretive Summary: Use of biochar by sheep: impacts on diet selection, digestibility, and performance
By Anne Zinn
A study recently published in the Journal of Animal Science investigated the influence of biochar obtained from exothermic production of lodgepole pine and quaking aspen on sheep performance, diet digestibility, and on preference for a ration enriched with this carbon-based material. Biochars are pyrolysis-based products typically used as a soil amendment to increase soil fertility, which then has positive effects on field water holding capacity, pH, cation exchange capacity, nutrient availability, and fertilizer use efficiency. The ability of biochars to bind to different chemicals and to absorb microorganisms and toxins make them appealing for their use in animal feeding systems as a way to enhance animal performance and reduce environmental impact. While there appears to be many benefits to its use, much of the scientific information available on biochars and livestock feeding comes from Eurasia and Oceania or from in vitro studies; information about in vivo utilization of biochars produced from the combustion of resources in North America and fed to sheep are limited, and it is unknown whether livestock can self-select biochar.
Results demonstrate that the addition of biochar to alfalfa/barley diets enhanced diet digestibility and influenced some ruminal parameters in sheep and some indicative of positive effects on lamb nutrition. Additionally, biochar addition to the ration or self-selection diet did not improve average daily gain or feed conversion efficiencies. Lambs offered a choice between rations with or without biochar preferred the latter diet. While there are possible positive effects of this supplementation, they were not reflected in significant improvements on average daily gain or feed conversion efficiencies in this study. Overall, longer periods of exposure to biochar than those provided in this study may be needed for observing significant differences in performance responses.
The full paper can be found on the Journal of Animal Science website.