Ovum Pick Up and in vitro Embryo Production using Sex Sorted Semen in Cows

Abstract

Background: Ovum pick-up, a technique for extracting immature oocytes from antral follicles, with in vitro embryo production, is a way to produce large number of embryos from live donors. Methods: By transvaginal ultrasound-guided ovum pick-up, oocytes were collected from large (9-19 mm), medium (4-8 mm) and small (2-3 mm) ovarian follicles of donor cows (n=8). The recovered oocytes were classified as A, B, C, D and E grades. Oocytes were subjected toin vitro maturation, fertilization (with sex sorted semen) and culture. Cleavage and blastocyst rates were recorded on day 4 and day 7 of culture respectively. Result: Total of 278 follicles were aspirated. The follicles aspirated per cow per OPU session was 12.67±1.86. The oocyte recovery rate was 45.31±7.35. Mean percentage of grade A, B, C, D and E oocytes was 15.69±3.91, 24.97±3.02, 37.53±3.45, 19.44±3.76 and 2.38±2.38 respectively. In vitro maturation rate (IVM%) was 91.71±2.38% and fertilization rate was 90.18±1.52%. Cleavage and blastocyst rates observed was 55.1±5.90 and 24.81±2.95% respectively. The mean percentages of different grades of embryos observed was, code 1: 21.13±2.78, code 2: 14.41±3.25, code 3: 19.56±4.11 and code 4: 44.9±5.90%. Transvaginal ovum pick up can be performed repeatedly without hormonal stimulation. Sex sorted semen can be used for in vitro production of female embryos.