Haryashvas were the sons of Daksha Prajapati and Asikini. They were the first to born of Maithuni Shrishti or through normal copulation. The births before that were outside the sphere of physical science – mostly it was referred as mind born. The story of Haryashvas is found in the Linga Purana and also in other scriptures.
The union between Daksha and Asikini produced 5000 sons. Sage Narada narrated about the fruitlessness of worldly pursuits to the Haryashvas. Sage Narada suggested that they should first gain knowledge and understand about worldliness and what is Real. So they went out in search of answer to questions posed by Sage Narada. They then became celibate and performed intense austerities. They never returned back to Prajapati.
Thus the aim of Daksha Prajapati to populate the world through Haryashvas was not fulfilled.