Control of oxidative phenomenon during gestation in monogastrics and ruminants

Abstract

In mammals, radical chains are necessary to support cell replication, differentiation and growth, as well as metabolic activity of different cell types. They have a very important effect in the course of gestation. The high metabolic rate of the uterus and conceptus (placenta and embryo), favoured by oestrogen secretion during this period of a mammals’ life, increases production of oxygen free radicals at different cellular locations, namely the mitochondria. They play a role in membrane fusion, which allows nidation of the embryon and remodelling of the uterine, placental and embryonic tissues, in the development of new blood vessel characteristics of gestation, settlement of cotyledons and the increase in membrane permeability, which allows an intensive influx of nutrients required by foetus development. Vitamins and minerals from the body stores of the gestating female are involved in preventing an unbalance between production and scavenging of oxygen free radicals (oxidative stress), which would lead to alterations of the organisms of the mother and foetus. Part of the vitamins is destroyed in the course of free radical trapping and part of the minerals is lost when the enzymes to which they are linked are inactivated by free radicals. The requirements of gestating females are therefore increased. Adaptation of the alimentary inputs must not only face these increased requirements, but also increases linked to the exposure to numerous stresses during their life, namely climatic stress. The latter decreases, in particular, cobalt content in the forages, and thus, lowers the synthesis in the rumen of vitamins B12 and B9 (folic acid), which are critical for the integrity of the maternal organism, for the development of the foetus, and for the achievement of gestation. Improvements of knowledge on these very scarcely studied aspects are necessary to promote a long lasting stable agricultural system of production.