https://www.thespainnews.es/news/3000-euros-for-consuming-eggs/788

Everyone who has chickens at home is obliged to register the birds, regardless of their use. In particular, “the owners of self-consumption farms will be obliged to make a prior notification to be included in the general register of livestock farms.” However, unlike large farms, self-consumption farms do not need prior authorization to be set up. The register, however, may vary according to the autonomous community. In Madrid, for example, farms with no more than 30 laying hens do not have to register.

But, i agree, it is a little too much paper and declaration for self-consumption only.