Muscle morphology andfibre type composition are briefly reviewed in relation to colour
stability and tenderness in beef, and water holding capacity, colour and eating quality in
pork. A large inter-muscle and inter-animal variation exists in meat quality, which is often
related to metabolic and contractile properties as determined by their muscle fibre type
distribution. Characteristics of dtgerent muscles may be modified in living animals by
environmental conditions andgenetic selection. Selection experiments based on biochemical
and histochemical characteristics determined in biopsies or otherwise, and study of correlated
selection responses, may lead to the development and applications of (new) muscle
traits in future breeding programmes.