Developmental capacity of goat oocytes collected from 5 degree C preserved ovaries

Abstract

Research has been conducted to study the effect of ovaries preservation at 5°C on the oocytes development capacity i.e the capacity of oocytes to undergo in vitro maturation (IVF), in vitro fertilization (IVF) and in vitro embryo development. Goat ovaries were obtained from slaughtethouse in saline solution containing 0.1% Bovine Sernm Albumine (BSA) and antibiotic and kept at 5°Cfor 3 and 12 hours. As cnntrol, untreated ovaries were kept for 3_hours at 30-35°C, the temperature usually used for ovaries transportation. The oocytes were aspirated from follicles with 2-5 mm in diameter using 20G needle connected to a 5 ml syringe containing modified phosphate buffered saline (mPBS). The aspirated oocytes were incubated in lOOp/ micro drops of tissue culture medium-199 (TCM-199) supplemented with 10% newborn calf serum (NBCS), 0.01 mg!~zl follicle stimulating hormone (FSH) and 50 pg/ml gentamycine sulphate for 24 hours at 38.5 'C in 5% C02 incubator. In vitro fertilization (IVF) was done irz C02 incubator at 38.5°C for 18 hours using fresh semen. Inseminated oocytes we;-e further cultured for 5 days. The matured and fertilized oocytes were examined by their nuclear status qfter aceta-orcein staining. The results showed that the average number of morphological normal oocytes collected from 5°C preserved ovaries were significantly lower than from the untreated control ovaries. After 24 h incubation the percentage of matured oocytes from the 3 and 12 h preserved ovaries were 85.3+2.8% and 75.5+2.2%, respectively (P<0.05); but were not significantly different with the untreated control ovaries 80.3 + 3. 7%. The i11 vitro fertilization and cleavage rate of oocytes colletected from 3 hours preserved ovaries were not significantly different from the control untreated ovaries. However, prolong 5°C preservation until 12 hours decreased the oocytes development capacity. In conclusion, preservation of ovaries in 5°C until 12 hours can produced oocytes capa!Jle to undergo in vitro maturation and f:?rtilization and support embryo development, and the oacytes development capacity were significantly reduced.