1. A system for estimating the volume, mass or weight of an individual animal comprising: a representation of an individual animal, generated from an image-capturing machine, stored on a computer readable medium; a virtual spatial model of a reference object; and a computer particularly programmed with the capability of reshaping the virtual spatial model, the representation of the individual animal, or both, into an approximate fit with each other; wherein the computer is particularly programmed to estimate the mass, weight, or volume of the individual animal as a function of an amount that the virtual spatial model, the representation of the individual animal, or both, were reshaped.