Year: 2020
Type: article
Abstract: The present study was conducted to evaluate the ovarian potential of 87 local ewes from Ngaoundere, Adamawa region (Cameroon) for in vitro oocyte production.The ovaries were excised, submerged in normal saline solution (0.9%) and transported to the laboratory for a detailed evaluation.Follicles on each ovary were counted, their diameters (Φ) measured and were grouped into 3 categories: small (Φ <2 mm), medium (2 ≥ Φ ≤ 4 mm) and large (4> Φ ≤ 10 mm).Each ovary was then sliced into a petri dish; the oocytes were recovered in Dulbecco's phosphate buffered saline, examined under a stereoscope (x10) and graded into four groups based on the morphology of cumulus oophorus cells and cytoplasmic changes of the oocytes.The effects of both ovarian (ovarian localization, corpus luteum, size and weight of ovary) and non-ovarian factors (breed, age, body condition score (BCS) and pregnancy status) on the follicular population and oocyte recovery rate were determined.The average follicular population was 8.80 ± 2.97 follicles per ovary.The number of small, medium and large follicles were 6.13 ± 2.90; 1.60 ± 0.49 and 1.06 ± 0.05, respectively.Oocyte recovery rate were 6.04 ± 1.01 per ovary.Oocytes graded I, II, III and IV were 1.20 ± 0.18 (11%); 1.23 ± 0.23 (14%); 1.13 ± 0.12 (7%) and 2.47 ± 0.93 (68%), respectively.The oocyte quality index was 1.98.Younger, non-pregnant ewes with a body condition score of 3 and large ovaries presented higher number of follicles and oocytes.Oocytes (grades I and II) acceptable for in vitro embryo production (IVEP) constituted 25% of the harvest.This study indicates that some factors such as age, body condition score, pregnancy status, ovarian localization, weight of ovary and corpus luteum must be taken into account to increase the potential of the ovary for IVEP.
Authors: Kouamo J, Simo A, Djitie Kouatcho F, Njintang Yanou N
Institution: University of Ngaoundéré
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W3096564537