This article highlights some old and new approaches that may be useful in assisting livestock-dependent people to meet their production objectives through the planning of diets and/or feeding strategies for their animals. It first describes the initial application of mathematical techniques based on linear programming (LP) using the simplex method or its derivatives. It explains that, although these simple applications have proved to be very effective in situations where one objective (generally profit maximization) is regarded as being overarching, they are of little use to livestock owners who keep their animals for multiple uses. Moreover, LP applications cannot identify near-feasible solutions that in many instances may be adequate for the user and more cost-effective. Although these drawbacks have been addressed by using a number of different approaches, each with its own merits, no single approach has been extensively adopted. Recent increases in desktop computing power and user-friendly software interfaces may, however, call for a re-evaluation of some of them.