Laparoscopic ovum pick-up for in vitro embryo production from dairy bovine and buffalo calves

Abstract

Laparoscopic ovum pick-up (LOPU) conducted on bovine and buffalo calves of 2-6-month of age, followed by in vitro embryo production and transfer into synchronous adult recipients, is a powerful tool for accelerated genetic gain and early dissemination of top genetics. In its current state, the technology is characterized by higher oocyte recovery rates, lower oocyte-to-embryo yields, and similar pregnancy and term development rates compared with adult counterparts. Improvements in oocyte competence have been made in recent years mainly through gonadotropin stimulation protocols tailored for prepubertal donors. These advances have brought the technology to the point of been apt for commercial application. However, future research must focus on increasing the proportion of fully competent oocytes recovered from calves thereby further empowering the role this technology platform can play in programs for accelerated dissemination of superior genetics.

In Vitro Production of Embryos from Prepubertal Holstein Cattle and Mediterranean Water Buffalo: Problems, Progress and Potential

“…In adult cows, the ovarian response upon gonadotropin stimulation is widely variable among animals [ 106 ]. The same variation was observed in calves [ 21 , 106 ], with research in our laboratory revealing similar results in both Holsteins [ 100 ] and buffalo [ 105 ] calves as shown in Table 1 . The large individual variation is problematic in selecting the best calves to be used in a prepubertal LOPU-IVEP scheme, which may be mitigated by determining the serum concentrations of anti-Müllerian hormone (AMH) given its correlation with an individual animal’s response following gonadotropin stimulation observed in adult cattle and buffalo [ 107 , 108 , 109 ].…”

“…Interestingly, we observed a steady decrease in polyspermy rates with age, declining from 45.5% in animals < 100 days old, to 12.8% in animals >130 days old [ 53 ]. We also observed similar results working with buffalo calves, with age and semen dose affecting polyspermy rates [ 105 ].…”

“…However, it is worth highlighting that LOPU has been shown to be extremely safe and can be repeated on a regular basis. For example, LOPU has been repeated ~10 times in goats [ 20 ], and we repeated the procedure every two weeks in prepubertal Holsteins and buffalo between 6 and 9 times over a 3–4 month period [ 105 ]. Following this, none of the animals had reproductive problems later in life, as they were used to produce more embryos by trans-vaginal OPU and had normal fertility following artificial insemination.…”

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

“…Over the past few decades, laparoscopic ovum pick-up (LOPU) has become the golden standard for the recovery of oocytes from live animals that are too small to be eligible for ultrasound-guided transvaginal ovum pick-up [ 1 , 2 , 3 , 4 , 5 ]. The concept was first described by Snyder and Dukelov in 1974, who recovered 6 oocytes from 21 follicles aspirated from an ewe under laparoscopic observation [ 6 ].…”

“…Furthermore, LOPU has also been identified as the method of choice for sourcing oocytes from deer and other wild ruminants in conservation programs [ 13 , 14 ]. Finally, oocyte collection by LOPU has also been used for accelerated genetic gain in prepubertal dairy cattle and buffalo [ 2 , 5 , 15 ].…”