RELATIONS BETWEEN FEEDING AND REPRODUCTIO N - REVIEW ARTICLE

Long-lasting effect of feeding (first of all the energy and protein su pply) has been reviewed on the reproduction of male and female animals . Energy deficiency does not harm permanently the embryonic developmen t of primordial germ cells. However even a slight feed deficiency in e we during the last 6 weeks of pregnancy or during the lactation period can worsen the future ovulation rate of lambs. Questions of nutriment supply and sexual maturation have been treated in case of both sexes. Thereafter the effect of feed doses on the number of ovulated eggs ha s been reviewed. Hormonal bases of flushing effect has also been treat ed. Fertility rate and survival of embryos determine the realization o f the potential of ovulated eggs. Incorporation rate of different nutr iments into the embryos has also been treated. Energy deficiency toget her with protein deficiency in highly pregnant dams diminish most firm ly the body-mass of offsprings to be born. System of lobulo-alveolar e pithelial cells in the mammary gland of ruminants develops mainly duri ng th pregnancy. The undernutrition not only diminishes the quantity o f colostrum but the start of milk production is also retarded. Nutrime nt supply has a significant effect on the length of period between bir th and refertilization. In this case, the restart of ovarian function is the key factor. Although deficiency of certain mineral matters (P, Mn,I) may also cause anoestrus, in most of practical cases disturbance s of energy and protein supply cause the most problems. Hormonal chang es in the background of the above mentioned processes have also been e valuated. Finally, the most important future research areas of the top ic have been prognosticated.