Laparoscopic Ovum Pick-Up Followed by In Vitro Embryo Production and Transfer in Assisted Breeding Programs for Ruminants.

Abstract

Simple SummaryIn vitro embryo production from oocytes collected by laparoscopy has the potential of producing more offspring from genetically superior females of ruminant species (e.g., sheep, goats, cervids) or ages (e.g., prepubertal cattle and buffalo) that are too small to be eligible for oocyte collection by the transvaginal ultrasound-guided method used in cows. This article reviews the multiple applications of the technology, how it is done, the pros and cons, the limitations to widespread use, and the envisioned improvements that are expected in the years to come. In small ruminants, where conventional embryo recovery is most commonly done by surgery, the technology offers a less invasive approach, i.e., more animal welfare-friendly and with minimum risks of surgical sequels. Thereby, it enables repeating the procedure in the same animals exponentially more times, resulting in the potential for an increased number of offspring born from elite donors. Furthermore, the emerging most attractive application is for the in vitro production of embryos from prepubertal animals at very young ages, which allows having progeny born from genetically superior donors before they reach the age and weight to be bred for the first time.The potential of laparoscopic ovum pick-up (LOPU) followed by in vitro embryo production (IVEP) as a tool for accelerated genetic programs in ruminants is reviewed in this article. In sheep and goats, the LOPU-IVEP platform offers the possibility of producing more offspring from elite females, as the procedure is minimally invasive and can be repeated more times and more frequently in the same animals compared with conventional surgical embryo recovery. On average, ~10 and ~14 viable oocytes are recovered by LOPU from sheep and goats, respectively, which results in 3–5 transferable embryos and >50% pregnancy rate after transfer. LOPU-IVEP has also been applied to prepubertal ruminants of 2–6 months of age, including bovine and buffalo calves. In dairy cattle, the technology has gained momentum in the past few years stemming from the development of genetic marker selection that has allowed predicting the production phenotype of dairy females from shortly after birth. In Holstein calves, we obtained an average of ~22 viable oocytes and ~20% transferable blastocyst rate, followed by >50% pregnancy rate after transfer, declaring the platform ready for commercial application. The present and future of this technology are discussed with a focus on improvements and research needed.