Dr. Theun Vellinga has over 30 years’ experience in animal husbandry research, ranging from grassland management and nitrogen utilization (grazing, fertilization, grass-maize crop rotation), agricultural nature management. International experience with livestock farming, GHG emissions, the cattle feed chain, manure management and the closing of mineral cycles. Also, intensively works with policy makers, the private sector and NGOs. Strongly focused on the application of developed knowledge in models and practical tools for users.