Integrating fertility preservation and cryo-banking into the conservation of rare and endangered deer species

Abstract

More than 50 deer species live in diverse ecosystems around the world. Unfortunately, most of them are threatened or endangered because of over-hunting, poaching or habitat destruction. Protection of wild populations (in situ) and management of animal collections in zoos and breeding centres (ex situ) are complementary conservation efforts relying on multidisciplinary approaches. Reproductive biology of deer species is one of the critical areas that still needs to be thoroughly studied to ensure the success of in situ or ex situ programs. Interestingly, there is a vast diversity in reproductive traits within the deer family (from anatomy to breeding-season patterns). On the basis of this fundamental knowledge, adapted reproductive biotechnologies have been developed to enhance reproduction and preserve fertility of individuals. Early works on artificial insemination (AI), in vitro fertilisation (IVF), and germplasm freezing in the more common red deer, sika deer and white-tailed deer have been highly inspiring to projects aiming at saving endangered deer species. A few fawn births following AI or IVF using frozen semen have been reported in wild species (e.g. Eld’s deer, Rucervus eldii thamin); however, assisted reproductive techniques and cryo-banking are currently not integrated into the management of rare and endangered populations. Knowing that many deer populations are rapidly declining in situ and ex situ, there is now an urgent need for better strategies and more fertility preservation options. The objectives of the present article are to review (1) existing reproductive biotechnologies to preserve fertility of different deer species and (2) how to integrate these approaches into the management of rare and endangered populations to address conservation issues.

Effect of Fixatives and Fixation Period on Morphology and Immunohistochemistry of Feline Ovarian Tissue

“…This is especially essential in cancer patients, who are at higher risk of losing their fertility due to gonadotoxic therapies [ 2 ]. Similarly, this technique fits well with the strategies of conservation of biodiversity or genetic salvage, wherein precious animals have to undergo gonadectomy or euthanasia or are otherwise found dead [ 3 , 4 ]. This is especially essential in endangered families, notably the wild Felids, where there is an absolute need to preserve the little genetic resource whenever there is a chance to do so.…”

Transcervical artificial insemination in the brown brocket deer (Subulo gouazoubira): a promising method for assisted reproduction in deer

“…In that context, several reproductive biotechnologies appear as part of conservation strategies 3 , 4 . Among these, germplasm banks are positioned as an essential strategy for ex-situ conservation of genetic resources, enabling the preservation of the genetic diversity of wild animals 5 , 6 .…”

“…An important reproductive biotechnique is artificial insemination (AI), which is widely performed in cervids via laparoscopic access 5 , 6 , 8 . However, there are also reports of AI with semen deposition in the vagina without cervical transposition 9 .…”

Spermatogenesis in a vulnerable South American cervid, dwarf red brocket (Mazama rufina)

“…Numerous species threatened with extinction could benefit from these techniques. However, assisted reproductive techniques are currently not integrated into managing protocols of rare and endangered populations (Comizzoli, 2020). Although the use of modern reproductive biotechnologies allows obtaining more offspring from selected parents to ensure genetic diversity, progress in non‐domestic threatened species will continue at a slow pace mainly because of the difficult access to biological material and the insufficient information on basic reproduction (Andrabi & Maxwell, 2007; Comizzoli et al, 2000).…”