Embryo transfer- saving of genetic variety of the Hungarian draft horse

SUMMARY Background: Although embryo transfer (ET) is considered to be a routine procedure in sport horses, it is only rarely used in Hungary. This is mostly due to financial reasons, even though the value of a foal born from a carefully selected and matched dam and sire may exceed the costs of embryo transfer by far. Objectives: Embryo transfer has not been performed in the Hungarian coldblooded horse before. The aim of our work was to prove that embryo transfer can be performed successfully in the Hungarian cold-blooded horse also. Materials and Methods: We used semen from “5787, Karancslapújtő 96 Kondor”, a chestnut dapplestallion belonging to the Belgian 28 male line to inseminate “Vilma”, a valuable grey mare belonging to the Belgian 22 bloodline suffering from hoof cancer. Three recipient mares were available during the program. Embryo flushing was performed 8 days after insemination. The uterus was flushed in a closed environment using Dulbecco’s phosphate buffered saline with added glucose (1 g/l), sodium pyruvate and kanamycin (0,36 g). Non-surgical, transcervical uterine lavage was performed on the donor mare. The equineCH 34 French-type catheter was fixed with the balloon in the caudal part of the body of the uterus to avoid losing any fluid or an embryo. Gravity was used to administer and to collect the fluid: the flush medium container was placed high while the bag collecting the fluid was placed close to the ground. The valve was closed after introducing 1 litre of pre-warmed medium, the recovered medium then flowed through the Y tube and an embryo filter (70 μmM-confilter) into an empty infusion bag. This procedure was repeated 6 times. Results and Discussion: Pregnancy examination by ultrasound proved that the procedure was successful, recipient mare No. 1 is pregnant. A healthy foal was born on the 15th of April 2018. The success of our program proves that embryo transfer may play a major role in preserving genetic diversity in the Hungarian cold-blooded horse in the coming years