Effect of successive ovum pick up on follicular development, and oocyte quality and quantity, in a commercial, buffalo (Bubalus bubalis) in vitro, embryo production program

YUPONI, R.; VALLEJOS, N.; BERDUGO GUTIERREZ, J.; KONRAD, J.L.; CRUDELI, G.A.

Foz do Iguazú

Simposio; International Ruminant Reproduction Symposium 2018; 2018

International Ruminant Reproduction Symposium

The first buffalo calf born after in vitro embryo production (IVP) was in 2004 and despite the fact that many research teams are working to improve buffalo embryo production, there are very few comercial IVP programs for buffalo. In addition, although researchers have attempted applying methods used in cattle to buffaloes, there are species differences in follicular size and number, quantity and quality of oocytes, embryo development, and the need to use specially designed medium that make IVP in buffalo of lower efficiency than in cattle. The aim of this study was to evaluate the effect of short term, repeated ovum pick up (OPU) on follicular number and quality of oocytes in a commercial buffalo IVP program. The study was conducted in Corrientes Argentina during the breeding season of 2017. Twenty mature and fertile Mediterranean and Murrah donors, body condition score 3/5 to 4/5 with no anatomical abnormalities were available for OPU, and were subjected to 3 sequential, weekly transvaginal, ultrasound guided aspirations, using a vacuum pump at 40 mm/Hg pressure attached to an 18-g needle. Antral follicle count (AFC) was performed before aspiration. Oocytes were recovered from folicular fluid and graded from I to IV according number of granulosa cells and cytoplasm. Follicle number, grade and quantity of oocytes were recorded, and data was analyzed using paired Student t test and Pearson correlation coefficients. Statistical significance was established at P < 0.05. Fifty-nine OPU were performed, and the time for each averaged 9 min. Five hundred follicles were punctured, and 260 oocytes were recovered (52%); of those, 9%, 20%, 34%, 35% were Grade I, II, III, IV, respectively. There were no differences in AFC (mean 7.2 per buffalo). There were differences in the number of follicles aspirated within the third (7.8) aspiration compared with the first (8.8) and the second (8.4). No correlations were found between number of follicles and recovered oocytes. Our results show that, in buffalos, the number of ovarian follicles declines after 21 days of aspiration, which has also been reported by others. Because buffalo females tend to produce lower quality oocytes than cattle, all oocytes recovered after OPU are used for embryo production. Although it may be necessary to increase the sample size to find correlations between follicle numbers and oocyte recovery, this research contributes with more information for commercial OPU buffalo programs to improve the efficiency of IVP. Rincon del Madregon Cabaña, UNNE, Universidad Nacional de Colombia.