Impact of FSH-Induced Ovarian Stimulation on Oocyte Recovery and In Vitro Embryo Production in the Red Sindhi Cows.

Follicle-stimulating hormone (FSH) plays an important role in regulating reproductive events, particularly follicular development and oocyte competence acquisition. Some studies using FSH protocols in zebu cattle were performed, but data regarding its application in the Red Sindhi breed are scarce and therefore warranted. In this context, this study aimed to assess the FSH administration regimen-multiple doses (T1-m) and single dose (T2-s) and coasting period (54 h vs. 102 h) in oocyte developmental competence in Sindhi females. A total of 80 mg of FSH was administered either as a single application (40 mg IM + 40 mg, SC) or compared to multiple applications (30 mg + 30 mg + 20 mg, IM). Animals that did not receive FSH treatment serve as controls (CT). The present data showed that both T1 and T2 applications resulted in a greater number of medium-sized follicles (7.80 vs. 8.57, p < 0.05), oocyte recovery (9.76 vs. 9.81), when compared to control (5.20; 6.30, respectively). Animals from T2 also had a greater number of aspirated follicles (12.52 vs. 8.70, p < 0.05), viable oocytes (7.33 vs. 4.45, p < 0.05) and blastocyst rates (43.22% vs. 29.11%, p < 0.05) than control animals. Our results showed that a reduced dose of FSH both single and multiple applications enhance oocyte developmental competence. Moreover, a single application of FSH combined with a longer coasting period offers practical advantages, making this approach more attractive for Sindhi breeding programmes.