If cow is a worship able, fish is also a worship able thing than cow. Fish is one of the avatars of ‘MAHA VISHNU’. (Mastyavataar). Then why don’t you ban eating fish? Pig is a avatars of Mahavishnu. This is the first Avatar of Vishnu. Muslims even don not touch the pig. Ox is also worshipped in hindu society as NANDI. But your daily life starts beating the Nandi while you start ploughing early in the morning. Cow is highlighted that this is eaten by Dalits and Muslims. You are finding political benefits. If it is your religious sentiment you should ban fish and pig first.