By the fifteenth century the demand for wool was having a measurable effect on English agriculture. Hoskins remarks that by 1500 the distinguishing feature of English lands was the preponderance of sheep, nearly three for every human. As we have seen, the shortage of labor and the net return from sheep raising favored a shift from traditional agricultural production. Livestock raising required little labor, at least compared to the effort required for traditional farming, yet it produced a high value for weight: a pound of wool, butter, or meat brought a larger monetary return than an equivalent weight of wheat. And sheep raising was feasible on land unsuitable for other agricultural activities. Because of these advantages, livestock farming became a major land use in Britain by the sixteenth century.