I have heard of yarns with milk, but I don't see the need to add milk to an input to make a garment (this is my personal opinion).

On the other hand, it's good that bamboo yarn exists to be in harmony with the environment.And raw or undyed cotton yarn also seems a good alternative. It seems that they are not so commercial where I live, it will be a reason for an intense search (haha), thank you very much for the information!.