Influence of rearing intensity on body development and milk production

Abstract

The ingenious biochemical system, which we generally call heredity, directs the body development and regulates the reaction of the individual in relation to the environmental conditions. It is this genetically determined adaptiveness of the individual which makes it possible for organic life to survive even when the climatic conditions and the supply of nutriment vary within wide limits in nature. The interaction of heredity and environment involves several problems of vital importance for animal production. One such problem is the influence of level of nutrition during the rearing period on body development, fertility, milk production and longevity. When investigating the relative importance of heredity and various environmental factors on the production traits in dairy cattle, we have concentrated much of our effort on this special problem.