A herd of 155 milk-producing cows populate the milk production unit of CATIE‘s commercial farm in Costa Rica. The cows are stabled for 6 hours per day, during which time they produce about 1,500 kg of fresh manure. The manure is separated into solid and liquid parts: The liquid is channeled into a 250 m3 bio-digester. The digester produces 30 m3 of biogas (consisting in 60-65% methane) each day. A generator converts the biogas into electricity, yielding about 67 kWh or 50% of the electricity used daily to operate the milking equipment. The liquid bio-slurry is used to fertilize the pastures. The solid manure is composted and used to fertilize the cut-and-carry pastures and CATIE’s sugar cane and coffee cultivation. The on-farm use of the liquid and solid manure products reduced the farm’s bill for synthetic fertilizer by at least 25%. It has also reduced the emission of greenhouse gases, mainly nitrous oxide, from the farm’s livestock.
The farm is an important center and showcase for education and environmental awareness in the region. Diverse groups of students, farmers, extension workers, policy makers, and members of civil society participate regularly in trainings and other events on environmentally friendly livestock production.