Effect of different factors on the recovery rate of oocytes for in vitro maturation and in vitro fertilisation procedures in sheep

Abstract

The effect of factors like the harvesting technique, size of the ovary, age of the animal and the presence or absence of corpora lutea on the quantity and quality of oocytes for IVM–IVF procedures was studied. Puncture and slicing yielded a larger number of oocytes per ovary than the aspiration method ( P<0.05). The slicing method resulted in the production of more debris, interfering in the recovery of oocytes. Puncture of the ovarian surface can be used as an alternative to aspiration and slicing, for harvesting of oocytes from sheep ovaries. Age of the animal had no significant effect on the number and quality of oocytes recovered. Due to the small size of the ovary in animals below one year of age, aspiration was difficult. Puncture and slicing yielded better results in this age group. The ovaries greater than 5×7×9 mm 3 in size yielded a greater number of oocytes, compared to ovaries less than 5×7×9 mm 3 by the aspiration method ( P<0.05). Differences were non-significant using the other two methods. The ovary with a corpus luteum yielded significantly lower number of oocytes than ovary without a corpus luteum ( P<0.05).