<div>Background: The availability of productive sows slaughtered in commercial and traditional pig slaughterhouses makes it possible to use their ovaries as a source of oocytes, which can be used as raw materials in the in vitro Maturation (IVM) process. Oocyte diameter is one indicator that determines the success rate of oocyte nuclear maturation in vitro. Scientific information on the relationship between the number and size of the follicles on the diameter of porcine oocytes is still very limited. Therefore, this research was conducted to add data that can later be used for in vitro Maturation and in vitro Fertilization. 
 
Methods: This research was carried on in 2021; samples were collected from sow ovaries from commercial and traditional pig slaughterhouses in Badung and Tabanan Regency. The aspiration oocyte collection method was carried out at the Embryology Laboratory of the Faculty of Veterinary Medicine, Udayana University. This research was conducted by grouping ovaries into three groups: group 1 is ovaries with small follicles that have a diameter &lt;2 mm, group 2 were ovaries with medium follicles which have a diameter of 3.1-5 mm and group 3 were ovaries with large follicles that have diameter &gt;5 mm. 
 
Result: The results showed that the larger the size of the follicle, the larger the diameter of the oocyte. There is a closer relationship between oocyte diameter and follicle diameter with a correlation value of 1 and has a very strong relationship with the number of follicles (negative relationship, correlation value = -0.703) and with oocyte quality (positive relationship with a correlation value 0.703). Oocyte quality correlated perfectly with follicle diameter and number of follicles (correlation value 1) and quite strongly correlated with oocyte diameter (correlation value 0.703). The close relationship between follicle diameter and the number of follicles on oocyte diameter is shown by the regression equation Y= 0.848 + 6.359X1 - 3.797X2 and the close relationship between follicle diameter and oocyte diameter on oocyte quality is shown by the regression equation Y= 0.900+ 0.310X1 + 0.005X2.</div>

Relationship between the Number and Size of the Follicle on the Oocyte Diameter of the Pig Ovarium