Hens were immunized with a macerate of goat and sheep placentomes. Immunizations were repeated every 15 days. Eggs were
collected over a period of 03 immunizations, IgY isolated, and its concentration measured. After 45 days of the start of immunization,
chickens were euthanized, their spleens isolated and fragmented for total RNA extraction by Trizol method. Performed the synthesis
of cDNA, was amplified by PCR the fragments of immunoglobulin G avian variable light chain (VL) and heavy chain (VH). Fragments
of VL and VH were used to constitute the final product by recombinant PCR-overlap process. The results present the feasibility
of building a library of scFv anti goats and sheep placenta opening the possibility of manufacture diagnostic kits for various
physiological situations of placental trophoblast cells belonging to these species.