7 First alpaca offspring produced from a demi-embryo

The objective of this study was to assess the feasibility of producing live offspring after transfer of alpaca demi-embryos. The study was conducted at Fundo Mallkini (Munañi, Azángaro province, Puno region, Peru) in the southern Andes Mountains at an elevation of 4,300 m above sea level. Eight Huacaya alpaca females were superovulated (Vivanco 2013 Proc. 29th Ann. Mtg. AETE, 43–74), and embryos were collected nonsurgically at 6.5 days post-mating. Most harvested embryos were allocated to an embryo cryopreservation study, but three hatched blastocysts were washed three times in 100 µL of fresh flushing medium (EMCARE™, ICPbio Reproduction) before being transferred individually into a 25-µL drop of splitting medium (ABT 360) devoid of any supplements; drops of splitting medium were placed in a 90 mm tissue culture-treated Petri dish with an inner surface that was scratched with a disposable injection needle in a grid pattern to create a rough surface onto which embryos were placed for bisection. When embryos were transferred to drops, they were aligned so that the inner cell mass (ICM) was on the left side of the drop to facilitate bisection from left to right with a firm, one-step cut (Vivanco et al. 1991 Theriogenology 35, 292). Care was taken to split the ICM and trophoblast cells into approximately equal halves. After each embryo was bisected, 200 µL of embryo-holding medium (EMCARE™, ICPbio Reproduction) supplemented with 10% (vol/vol) alpaca serum was added to the splitting medium to aid in recovery of the demi-embryos. All embryo handling was performed at 25°C. After bisection, each demi-embryo was transferred individually into 200 µL of embryo-holding medium supplemented with 10% (vol/vol) alpaca serum until being loaded in a 0.25 mL straw for nonsurgical transfer into a synchronous recipient. From the 6 fresh demi-embryos that were transferred, one pregnancy was established (16.7% pregnancy rate). This pregnancy resulted in birth on February 10, 2020, of a male offspring possessing a normal birthweight of 8.6 kg after a gestation of 331 days. To confirm that the offspring originated from the bisected embryo, DNA microsatellite marker analysis was performed. The offspring shared 14 markers with the embryo donor and breeding sire (LCA37, LCA5, LCA66, LCA8, LCA90, LCA94, VOLP04, VOLP32, VOLP55, VOLP72, VOLP92, YWLL36, YWLL44, YWLL08), but did not share three markers with the recipient female (LCA05, LCA08, LCA37). Results indicate that it is feasible to produce healthy alpaca offspring after transfer of fresh demi-embryos. To the authors’ knowledge, the offspring produced in this study is the world’s first alpaca offspring produced from a demi-embryo.

This research was partially supported by the Marion Eugene and Audrey Ensminger Endowment at Iowa State University.