Artificial insemination techniques available include intracervical insemination and intrauterine insemination. After multiple failed attempts at artificial insemination, they attempt in vitro fertilisation. Like dragonflies, they reproduce using indirect insemination and delayed fertilisation. Taurine has been used in some cryopreservation mixes for animal artificial insemination. There are multiple methods used to obtain the semen necessary for artificial insemination. Offspring can occur after mating or after artificial insemination. Research into the paternity of offspring produced by traumatic insemination has found "significant" last-sperm precedence. In many species that engage in bilateral insemination, sperm trading is conditional. Some litters were produced using artificial insemination. The calf was conceived via artificial insemination. Therefore, breeders must undertake artificial insemination of female dogs. Single women can be treated by known or anonymous donor insemination. Some of Jacobson's patients who had conceived through donor insemination agreed to genetic testing. Most purebred dairy calves are produced by artificial insemination (AI). In spite of several artificial insemination experiments there were no offspring.