Collection and In Vitro Maturation Of Cat Oocytes Obtained From Different Oestrous Cycles

Abstract

As a felin, cat has a similarity in biological reproduction with the tiger. To conserve the tiger (especially Sumatran tiger), cat could be used as a model to study the in vitro embryo production technology. The purpose of this study was investigate the quality and quantity of the oocytes collected from different status of the ovaries and maturation in vitro Oocytes were collected from ovaries by aspiration. Ovaries were removed by laparotomy surgery from 15 local female cats, age 1-3 years, weight 2.5-3.5 kg. The oocytes were maturated n vitro in maturation medium (TCM-199 supplemented with 0.01 mg/µl follicle stimulating hormone and 5% female cat’s serum) during 8, 22, 26 and 30 hours of incubation at 37⁰C in humidified atmosphere of 5% CO2 in air. From the ovaries in follicular phase (n=8), 686 oocytes were collected, consisted of 14 (21%) oocytes with homogenous cytoplasm and complete cumulus cell (grade A), 117 (17%) oocytes with homogenous cytoplasm and incomplete cumulus cell (grade B), 134 (20%) oocytes with homogenous cytoplasm without cumulus cell (grade C) and 288 (42%) degenerated oocytes (grade D). From the ovaries in luteal phase (n=7), 407 oocytes were collected, consisted of 109 (17%) oocytes of grade A, 98 (24%) oocytes grade B, 77 (19%) oocytes grade C and 123 (30%) oocytes grade D. The maturation rate of cat oocytes were 14%, 4/29, 27%, 7/26; 38%, 8/21; and 10%, 10/31 for 18, 22, 26 and 30 hour of incubation, respectively. These results showed that cat oocytes could be collected from both ovaries in follicular phase or luteal phase, and the oocytes were matured after more than 22 hours of incubation, respectively. These results showed that cat after more than 22 hours of incubation in vitro.