Oestracton 52.4 is used to synchronize ovulation in cattle, horses, and pigs. It contains Gonadorelin (6-D-phenylalanine) acetate, a synthetic analogue of the naturally occurring hormone GnRH. This medication stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are crucial for follicle maturation and ovulation.