In the early twentieth century, crossbreeding between the Thoroughbred and the Akhal-Teke took place, aiming to create a faster long-distance racehorse. The Anglo Akhal-Tekes were not so resilient however, as their Akhal-Teke ancestors, and many died due to the harsh conditions of Central Asia. After the endurance race from Ashkabad to Moscow in 1935, when the purebreds finished in much better condition than the part-breds, the studbook management decided to consider all crossbred horses born after 1936, as not purebred. Horses with English Thoroughbred ancestors born prior to that date were allowed to remain inside the studbook (e.g. 044 Tillyakush, grandson of Thoroughbred Burlak, 831 Makh, granddaughter of Thoroughbred Blondelli and great-great-granddaughter of Thoroughbred Junak, and line founder 9 Ak Belek, a direct descendant in the male line of the Thoroughbred stallion Fortingbrass). Due to this fact there doesn't exist any Akhal-Teke today whose ancestry doesn't contain a Thoroughbred. Since 1973, all foals must be blood typed to be accepted in the stud book in order to protect the integrity of the breed. From 2014 on, a DNA test based on hair follicles is sufficient if the DNA of the parents is on file. A stallion not producing the right type of horse may be removed. Nowadays, artificial insemination is allowed as well as embryo transfer. The surrogate mother, however, needs to be a pureblood Akhal-Teke mare for the foal to be registered in the General Studbook as a pureblood Akhal-Teke.