Optimization of recovery and maturation methods for cumulus‐oocyte complexes in jennies

• Published in: Reproduction in domestic animals 2023-01, Vol.58 (1), p.168-175
• Main Authors: Dai, Shizhen, Di, Zhengyang, Li, Nan, Zeng, Shenming
• Format: Article
• Language: English
• Subjects: Abattoirs; Animals; COCs morphology; Diameters; donkey; Embryo, Mammalian; Equidae; Female; Follicles; Gametocytes; In Vitro Oocyte Maturation Techniques - methods; In Vitro Oocyte Maturation Techniques - veterinary; Livestock; Maturation; maturation medium; Oocytes; Optimization; Ovaries; Ovary; ovum pick‐up; Recovery
• ISSN: 0936-6768; 1439-0531
• DOI: 10.1111/rda.14276

Embryo production in donkeys is inefficient compared with that in other livestock. Obtaining a sufficient number of MII oocytes is the first step to solving this problem. In this study, the number, morphology and maturation rates of cumulus‐oocyte complexes (COCs) obtained from abattoir‐derived ovaries or live jennies were compared. The diameter of follicles from abattoir‐derived ovaries was measured and divided into group 1 (2–6 mm), group 2 (6–10 mm), group 3 (10–20 mm), group 4 (20–28 mm) and group 5 (>28 mm). The results showed that the number of follicles per ovary in group 2 (3.6 ± 0.28) and 3 (4.2 ± 0.90) was higher than that in the other groups (p 35 mm) were aspirated from live jennies using OPU. Although there was no difference in the recovery rates of COCs between group 3 and OPU (48.8% vs. 43.0%, p = .184), the percentage of grades A COCs in group OPU was higher than group 3 (72.5% vs. 59.3%, p = .036). There was no difference in the maturation rate between group 3 and OPU (60.3% vs. 69.3%, p = .171) after the COCs matured in vitro. The rates of recovery (72.2%) and maturation (92.3%) in group OPU‐Preov were higher than those in other groups (p