Julio Landinez-Aponte, Zhongde Wang
The alpaca (Vicugna pacos) is a domesticated South American camelid of increasing global relevance, valued for its high-quality fiber, cultural significance, and unique biological traits including heavy-chain-only antibodies. Its reproductive physiology differs fundamentally from that of conventional livestock, encompassing an induced rather than spontaneous ovulatory mechanism in females and an unusually viscous ejaculate in males, differences that constrain the direct application of protocols developed for cattle, sheep, and swine and that have historically limited the pace of genetic improvement in the species. This review provides an integrated account of alpaca reproductive anatomy, follicular and neuroendocrine physiology, seminal plasma biochemistry, and semen cryopreservation, together with the current state of artificial insemination, multiple ovulation and embryo transfer, laparoscopic ovum pick-up, in vitro embryo production, and intracytoplasmic sperm injection. By examining female and male reproductive biology within a single mechanistic framework rather than treating each in isolation, this review draws out the regulatory pathways that connect the two systems and identifies the knowledge gaps that a fragmented, single-sex treatment of the subject would otherwise leave unaddressed. Particular attention is given to the biological determinants that most directly limit ART efficiency and to the translational steps required to move current protocols from experimental proof of concept toward standardized, field-applicable practice. Building on prior reviews that have illuminated individual ART modalities and single-sex reproductive biology, this work is intended to support researchers and practitioners advancing reproductive technology in camelids and the broader effort to conserve and genetically improve alpaca populations worldwide.