Bava Metzia 69 - Half-and-half Venture
One can assign an animal to a shepherd to be raised, sharing in profit and loss. The shepherd needs to be paid wages, for otherwise his service constitutes interest on that half of the animal that is a loan. The offspring represents profits and can be divided.
If the shepherd continues to care for the offspring after the prescribed time of growth, he now takes ¾ of the new profits. Half of the offspring is his, and the other half constitutes a new half-and-half venture.
One may pay an independent son of a lender in order to obtain a loan from his father, and it is not considered interest.