Is it permissible to establish fish farms and cow farms for milk production?

It is permissible for a Muslim to establish farms for raising fish or cattle for dairy production. This work falls under "a man's earning by his own hand," which is considered among the best types of earnings, provided that he fears Allah in his work and does not harm people. It has been narrated in the Hadith (definition): "Which earning is the purest?" He said: "A man's work with his own hand, and every righteous transaction." And "No one has ever eaten food better than that which he has eaten from the work of his own hand. And indeed, the Prophet of Allah, Dawud (peace be upon him), used to eat from the work of his own hand."