Śatapatha Brāhmaṇa ("of a hundred paths") 4.5.7.4

4.5.7.4

sa yadi gharmadughā hvalet | anyāmupasaṃkrāmeyuḥ sa yasyāmevainaṃ velāyām purā pinvayanti tadvaivaināmudīcīṃ sthāpayedagreṇa vā śālām prācīm

Now should the cow, which supplies the gharma, fail (to give milk), let them go to another; and at the same place where they otherwise make that gharma (milk) flow, let them place her with her head towards the north, or in front of the hall with her face to the east.