Mahabharata 12.60.26

12.60.26

na ca vaiśyasya kāmaḥ syānna rakṣeyaṃ paśūniti |
vaiśye cecchati nānyena rakṣitavyāḥ kathaṃcana || 26 ||

With proper attention he should also protect and rear all (domestic) animals as a sire protecting his sons. Anything else that he will do will be regarded as improper for him. By protecting the (domestic) animals, he would obtain great happiness. The Creator, having created the (domestic) animals, bestowed their care upon the Vaisya. Upon the Brahmana and the Kshatriya he conferred (the care of) all creatures. I shall tell thee what the Vaisya's profession is and how he is to earn the means of his sustenance. If he keeps (for others) six kine, he may take the milk of one cow as his remuneration; and if he keeps (for others) a hundred kine, he may take a single pair as such fee. If he trades with other's wealth, he may take a seventh part of the profits (as his share). A seventh also is his share in the profits arising from the trade in horns, but he should take a sixteenth if the trade be in hoofs. If he engages in cultivation with seeds supplied by others, he may take a seventh part of the yield. This should be his annual remuneration. A Vaisya should never desire that he should not tend cattle. If a Vaisya desires to tend cattle, no one else should be employed in that task. I should tell thee, O Bharata, what the duties of a Sudra are. The Creator intended the Sudra to become the servant of the other three orders. For this, the service of the three other classes is the duty of Sudra. By such service of the other three, a Sudra may obtain great happiness.