The building in the Tréby hamlet of Donnas, which from 1897 until 1980 hosted the activity of the local social dairy has a double historical and cultural interest as it testifies at the same time to the rural past of the village and to the centuries-old presence in Donnas of the Confraternity of the Holy Spirit, whose charitable activity has survived almost to the present day.

While the premises used up to thirty years ago as a social dairy preserve nowadays the furnishings and equipment for the delivery of milk and the subsequent dairy processing, as well as the documentation and records relating to the operation of the company itself, in the adjoining room, entirely frescoed , the evidence of the activity of the “Confrèrie du Saint-Esprit” emerges, existing since 1012 as reported on the fresco depicting the Last Supper.
You can admire various paintings attesting the work done by the brotherhood in favour of the community. The duty of the confraternity was in fact to translate faith into works of charity, distribute food to the poor and host the homeless in case of fire. The charitable activity of the confraternity continued for more than a century and a half after its official suppression in 1776.

The act establishing a local dairy at Treby dates back to the 25th July 1897.
Five years later, on the 21st May 1902, the dairy bought the buildings of the Brotherhood of the Holy Ghost, where it remained in activity until 1980, when the association broke up.

The building, given to the Municipality of Donnas in year 2000, has been restored and destined, in 2003, to ethnographic museum, furnished with the same equipment and materials originally used at the dairy.