Early pregnancy: Concepts, challenges, and potential solutions

Early pregnancy encompasses the period from formation of the zygote after fertilization in the oviduct to the establishment of pregnancy and implantation of an elongated conceptus in the uterus. Important facets of early pregnancy in livestock include: The success of early pregnancy has a major influence on production and economic efficiency of livestock enterprises. The majority of embryo loss occurs during the first two to three weeks of pregnancy in ruminants and first month in pigs. Nutrition, disease, environment, and genetics are important determinants of early pregnancy success. Genomic technology is expected to improve our understanding of the underlying complex biological processes involved in pregnancy and provide useful tools to decrease embryo mortality in livestock. By increasing fertility, the efficiency and sustainability of livestock production enterprises can be maximized.