The effect of garlic oil, xylanase enzyme and yeast on biomethane and carbon dioxide production from 60-d old Holstein dairy calves fed a high concentrate diet
Garlic oil quadratically decreased CH4 production. Xylanase, yeast and garlic oil decreased CO2 production. Increasing level of xylanase and yeast increased CO2 production. Natural additives can sustainably mitigate against environmental pollution by reducing greenhouse gas emission from calves.