Programación metabólica de la eficiencia alimentaria en corderos: efecto de la restricción de alimento en la etapa de lactancia y mecanismos moleculares implicados = Metabolic programming of lamb feed efficiency: effect of feed restriction during the suckling period and molecular mechanisms involved

Abstract

The prospects for world population growth and the increased demand for animal products bring on a future scenario of increased competition for resources between man and livestock, which has led to the search for new production strategies to increase feed efficiency of farm animals. However, increased feed efficiency could compromise other traits such as growth rate, carcass and meat quality, as well as animal health and welfare. Therefore, it is essential to know the molecular factors and mechanisms that determine individual differences in the efficiency of feed resources use, but with a holistic approach that integrates the different objectives that society demands: feed efficiency, animal health and welfare, quality of products and environmental impact.One of the key factors in feed efficiency is the nutrition received by the animal during the early stages of life (pre and postnatal nutrition), since it can cause long-term changes in gene expression in different organs and tissues and, consequently, in the metabolism during the adult stage.Nevertheless, most of the studies carried out on metabolic programming have been raised from a health perspective, evaluating the effect on the incidence of metabolic pathologies during the adult stage. The relation with feed efficiency has been studied hardly, especially in ruminant species. Furthermore, much of the research has focused on the effect of feed restriction during the prenatal period, with few studies on the effect of restriction during the early stages of life (during the suckling period).Metabolic programming offers the possibility of designing early nutritional interventions that allow modulating feed efficiency and animal productivity during later stages of life. Therefore, it is necessary to identify the factors (age, type of restriction, duration of the restriction, etc.) and the molecular mechanisms involved to design effective strategies.For all this reasons, the present studies were raised with the overall objective of studying the effect of a moderated feed restriction during the suckling period on feed efficiency of lambs during postweaning phases (fattening and replacement), as well as the underlaying molecular mechanisms involved in the process.