“…They include members of the transforming growth factor β (TGF-β) superfamily that are vital intraovarian growth factors (Table 1) (Santibanez & Kocic, 2012). This superfamily comprises over 34 family members, the most important ones that are associated with litter size are bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) (Abdurahman et al, 2019;Imran, Al-Thuwaini, Al-Shuhaib, & Lepretre, 2021;Ali, Kadhim, & Al-Thuwaini, 2022). BMP15 and GDF9 are released by ovarian follicles, leading to the transformation of primary follicles to the basal form (Castro, Cruz, & Leal, 2016;Ajafar, Kadhim, & AL-Thuwaini, 2022), and involved in follicular and oocyte maturation, proliferation/atresia of granulosa and theca cells, steroidogenesis, ovulation, and corpus luteum formation (Chu et al, 2018).…”