Preserve genetic material for use in future captive breeding programs
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 2
Background information and definitions
Assisted reproductive technology is advancing rapidly. For rare mammals, preservation of genetic material provides potential to increase reproductive output from a small number of individuals and to retain embryos or other material for future development.
Note that many relevant studies may be documented in journals that are not primarily conservation-related and which are, therefore, not included in our systematic searches for evidence.
Supporting evidence from individual studies
A study (date not stated) in a zoo in Mexico (López–Saucedo et al. 2013) found that using a series of non-traditional techniques, combined with natural mating, five embryos were produced from aoudad Ammotragus lervia that could be cryogenically preserved. The five embryos were obtained from just one of the three female aoudad, with the low embryo recovery rate being due to a low level of fertilization in vivo. The oestrus and superovulation of three female aoudad were synchronized. Procedures followed those used for domestic sheep combined with subcutaneous osmotic pumps for delivering the follicle-stimulating hormone. An aoudad ram was introduced for natural mating at the anticipated time of oestrous. Embryos were collected five and a half days later by incision through the abdominal wall. Embryos were cryopreserved, for use in conservation breeding programs (potentially by transferring to surrogates, such as domestic hybrids between aoudad and sheep or goats).Study and other actions tested
Referenced paperLopez-Saucedo J., Ramon-Ugalde J.P., Barroso-Padilla J.D., Gutierrez-Gutierrez A.M., Fierro R. & Pina-Aguilar R.E. (2013) Superovulation, in vivo embryo recovery and cryopreservation for Aoudad (Ammotragus lervia) females using osmotic pumps and vitrification: a preliminary experience and its implications for conservation. Tropical Conservation Science, 6, 149-157
A controlled study in 1989–1998 and 2008–2011 in two captive facilities in Wyoming and Virginia, USA (Howard et al. 2016) found that artificial insemination using preserved genetic material increased genetic diversity and lowered measures of inbreeding in a captive population of black‐footed ferrets Mustela nigripes. Genetic diversity of the captive population was greater when eight black-footed ferret kits (and their offspring) born as a result of artificial insemination with preserved semen were incorporated (86.5–86.8%) than when the population reproduced naturally (86.3–86.6%). Inbreeding also decreased by 6% (data reported as inbreeding coefficients).In 1989–1998, semen were collected from 16 male ferrets (1–6 years old) by electroejaculation and cryopreserved in liquid nitrogen for 10–20 years. In 2008–2011, a total of 18 female ferrets were inseminated with the thawed samples. Their eight offspring went on to produce 32 offspring and grand-offspring by natural mating. Selection of female recipients was based on the analysis of the pedigree of the captive population.Study and other actions tested