What is the ruling on raising animals for ornamental purposes while preventing them from procreating, and is the owner sinful for preventing the male rabbit from reaching the female despite its continuous attempts to do so?

It is permissible to raise animals such as rabbits in homes in special cages for benefit or decoration, whether male or female, together or separately. This is indicated by the Prophet's (peace and blessings be upon him) حديث with Abu Umayr: "O Abu Umayr, what happened to the little bird (Nughayr)?" Al-Hafiz Ibn Hajar mentioned that among the benefits of this hadith are the permissibility of spending money on permissible things that entertain a child, and the permissibility of keeping birds in cages. There is no harm in preventing them from what you mentioned.