Professor David Grainger Marcus Wood-Gush FRSE (20 November 1922 – 1 December 1992) was a South African-born animal geneticist and ethologist based for most of his professional life in Edinburgh. He was an expert on animal behaviour and academic author in this field. He was one of the first to study the impacts of factory farming. He advocated the study of animal behaviour to gauge what implied "humane treatment" for different species, and tried to balance these factors against economic viability for the farmer. He looked at the impact of stress upon animals and held that animals should be treated as individuals not as a "commodity". In these studies he concluded that food supply was the essential factor in controlling animal behaviour.