Matsya Purana 207.34

207.34

purastādudyato nīlo vṛṣabhaśca praśasyate.
śaktidhvajapatākāḍhyā yeṣāṃ rājī virājate .. 207.34 ..

Similarly a black bull having all those things white is said to be the same The bull whose tuft of hair at the tail end may be long enough touching the ground, and the hairs of the tail long and thick, such a Nîla bull is said to be specially good The bulls having the signs of a pearl, a banner, etc, are exceptionally good They are the givers of wonderful Siddhis and victory The bulls when obstructed in their motion stop, and whose head and neck are elevated, are excellent. Those that have their forepart of the horns and the eyes red, body white, hoofs resplendent like coral, are said to be the best of all These are to be kept in the house or set at liberty These increase grains and wealth The bulls should always be examined before being set at liberty or kept in the household The bull whose four feet, face and tail are white, and whose colour is red like the juice of lac or red dye is known as Nīla vṛiṣabha It should be set free, it should never be kept in the household It is a saying amongst the household that one should desire many sons for even if one son out of a many goes to Gayā or offers a Gaurī (virgin) or sets a Nīla Vṛiṣabha at liberty his family is blessed—33-41