Pregnancy-associated glycoproteins (PAGs): clinical application for pregnancy follow-up in Buffalo Cow

Pregnancy diagnosis is an important part in reproduction management of ruminant and pregnancy loss has a remarkable impact on the fertility of domestic animals. Buffalo are considered to have low reproductive efficiency also in relation to the seasonality of the species. Most of the embryonic losses occur during the first days after fertilization and during the process of implantation. For that reason it is very important to discriminate, with an early pregnancy diagnosis, pregnant from non pregnant animals particularly when breeding technique such as “out of breeding season mating” or artificial insemination are applied. In the last years, a large polymorphic family of placenta-expressed proteins has been discovered in ruminant species and used for pregnancy diagnosis. Members of this family are named pregnancy-associated glycoproteins (PAG), being synthesized in the mono-and binucleate cells of the ruminant’s trophectoderm. Part of them are released in the maternal blood circulation where they can be assayed by different laboratory techniques. Recently, Barbato et al. (2013), by using biochemical procedures, have isolated from buffalo cotyledons different molecules of the PAG family that have been used to produce antisera for radioimmunoassay (RIA) development. With this method is possible to distinguish between pregnant and no pregnant buffaloes starting from day 25 of gestation. Moreover, the use of PAG assay is useful throughout the gestation period in order to revel the presence of incorrect pregnancy diagnosis and embryonic/fetal mortality. The PAG assay can help veterinarians and breeders in the management of reproduction and represents a powerful tool for investigator involved in studying factors affecting embryo and fetal mortality.