Background information and definitions
During programmes to rear endangered animals in captivity, in preparation for reintroductions into the wild, artificial insemination may be used to initiate pregnancies. The technique may be used instead of natural mating in situations such as animals being kept at different facilities or where natural mating has failed. It may also be carried out using preserved sperm for purposes of maintaining genetic diversity.
Studies included here are those identified by our searches of conservation journals. It is likely that other relevant studies exist in biological journals that specialise in reproduction.
Supporting evidence from individual studies
A study in 2008–2011 in two ex-situ facilities in Wyoming and Virginia, USA (Howard et al. 2016) found that following artificial insemination, fewer than half of female black‐footed ferrets Mustela nigripes gave birth. Five out of 18 (28%) artificially inseminated female black-footed ferrets gave birth. Eight kits were born. Six of those kits subsequently went on to breed by natural mating. Kinship (a measure of relatedness within a population) was lower among these kits and their descendants than among the population as a whole. The study was conducted at the National Black‐Footed Ferret Conservation Center and at the Smithsonian Conservation Biology Institute. Ferrets were managed in individual cages (1.0–3.6 × 1.3–6.0 m). Semen was collected from adult ferrets (1–6 years old) by electroejaculation and cryopreserved for 10–20 years. Females were inseminated by transabdominal injections of sperm.Study and other actions tested
A study in 2012–2013 in an ex-situ facility in São Paulo, Brazil (Oliveira et al. 2016) found that following artificial inseminated, a captive female Amazonian brown brocket deer Mazama nemorivaga gave birth. Seven months after being artificially inseminated, a female Amazonian brown brocket deer gave birth without veterinary intervention to a healthy male fawn. A captive adult pair of Amazonian brown brocket deer was kept in isolated pens in a deer research facility. Animals were exposed to natural light conditions and given similar diets. Every morning for one month, a trained examiner manually observed the female for signs of natural oestrus. Eight hours after oestrus was detected, the female was physically restrained, anesthetized and inseminated. Sperm was collected by electroejaculation. Tools and techniques used for artificial insemination were based on those from procedures carried out on sheep and other small ruminants.Study and other actions tested
A replicated study in 1996–2016 in Sichuan Province, China (Li et al. 2017) found that following artificial insemination, a lower proportion of 78 captive female giant pandas Ailuropoda melanoleucahela became pregnant than after natural mating. Following artificial insemination, a lower percentage of female pandas became pregnant (19%) than following natural mating (61%). However, there was no significant difference in the litter size of females inseminated artificially or through natural mating (data reported as model results). Between 1996 and 2016, seventy-eight female pandas held in open-air enclosures at two facilities were subject to 65 attempts at artificial insemination and 150 attempts at natural mating. Natural mating was always attempted first but, in cases of excessive aggression between males and females, artificial insemination was used instead.Study and other actions tested