Effects of feeding exogenous vitamins and microelements on follicular development and molecular function of granulosa cells in donkeys

In mammalian ovarian physiology, vitamins and microelements are essential for follicular development, ovulation, and the synthesis and secretion of hormones and growth factors. However. the molecular mechanisms by which they influence maturation and growth of follicles in donkeys are still unknown. Here, we investigated how vitamins and microelements affected the development of follicles and the proliferation of ovarian granulosa cells (GCs). For this experiment, 40 jennies (average body weight: 292.946±33.543 kg, age: 3∼4 years) were randomly assigned into 4 groups (n=10) and fed 50% (A), 75% (B), 100% (C), and 150% (D) of a mixture of vitamins A, D and E and microelements once a day (dose 5 ml) for two consecutive months. After that, ultrasonography was applied to record the change in follicular dynamics in three estrous cycles. Using a transvaginal ultrasound-guided aspiration device to obtain follicular fluid (containing GCs) from the follicles (Ф=30mm-35mm), multi-omics analysis revealed its molecular mechanisms and physiological functions. The results showed that the time required for growing follicles to reach ovulation (Ф>40mm) was shortened in the vitamin D group compared to the three other groups(P