Some ecologically minded dairy farmers in Sarapiquí, in the northeastern lowlands of Costa Rica, have come up with an advanced recycling system in which Holstein cows more suited to Alpine highlands feel fresh and cool in the Caribbean tropics by means of fans run by power derived from their own manure.

The Pozo Azul dairy farm has become a tourist attraction because of its unusual, economical and environmentally responsible way to get 180 Holstein cows to produce milk and electricity in a hot climate.

The black-and-white dairy cows not only survive the heat but also produce 2,000 quarts of milk a day through a ventilation system that keeps them moist, cool and comfortable.

The animals' natural habitat is more than 1,500 meters (5,000 feet) above sea level and is characterized by very low temperatures, to the point that adapting the species to the torrid Caribbean climate was considered unlikely – if not impossible.

Rather than a luxury, the unusual cooling idea is a model of sustainable savings, because in addition to giving milk, the cows provide fertilizer and contribute to generating electricity and preserving the environment.

Pozo Azul is in La Virgen de Sarapiquí, a town 79 kilometers northeast of San Jose, only 150 meters above sea level, where temperatures may soar to up 38 C (100 F) in the summer, a deadly environment for the Holsteins.

More than 10 years ago, inspired by similar projects they had seen in Arab countries, Alberto Quintana and his family, owners of Pozo Azul, set up gigantic fans outfitted with hoses that spray water into the environment.

"The breeze generated by the fans, on top of the water from the hoses, lowers the temperature in the stockyard to 15 C (59 F), said Max Martínez, who manages the dairy.

The cooling system effectively simulates the cow's natural environment, presumably making them feel comfortable in the midst of the warm Caribbean climate.

The fans run on electricity generated by methane gas extracted from the dung of the same cows who get the “cold benefit.”

“We have a system in which everything is recycled. The cows' excrement goes into a tank where it is subjected to high-pressure water so it will lose texture, then goes through three filters to extract the thickest fiber,” Martínez says.

The final product goes into a container called a “biodigestor” that extracts methane gas from the dung. The gas then passes through two other machines that convert it to electricity.

What remains of the excrement goes into another tank where worms feed on it and produce an organic fertilizer used on the ranch's pasture and banana plantation.

The animals are sheltered in an open stable, where individual stalls allow them to feed comfortably.

They eat a “special formula” made up of bananas and grass from the farm, concentrated feed, vitamins and minerals so they will yield the quality milk the farm sells.

When it's milking time, all that is needed is for one of the farm's 10 employees to whistle, and the animals will walk toward the dairy area to patiently wait for their turn.