Vol. 12, Issue 6 (2023)

Author(s):
Pradeep Chandra, Brijesh Kumar, Sushobhit Singh, Kalpendra Kohli, Bhagirathi, Vandana, MK Patra, VS Chouhan, SK Singh and Harendra Kumar

Abstract:
The present study aimed to find the follicular and ovarian changes during superovulation and post-flushing luteolysis pattern. Sahiwal donor cows (n=10) were superstimulated using (STIMUFOL®/pFSH) during the mid-luteal phase and were monitored for follicular development during superovulation and post-flushing luteolysis changes were recorded using trans-rectal ultrasonography. At the initiation of FSH administration (10^th day), the mean number of small follicles was significantly high, whereas on the day of prostaglandin (PG) injection (12^th day), a significantly greater number of medium follicles were observed (p<0.001) and at superovulation estrus (SOE/14^th day) significantly higher number of large follicles were recorded. Also, a significantly higher number of corpora luteum and the luteal areas was recorded on the day of flushing compared to any other day of superovulation protocol. Similarly, ovarian size was significantly larger on the day of flushing for both the right and left ovaries. Post-flushing administration of PGF₂ alpha to Sahiwal donors leads to a significant reduction in the area of corpus luteum within 72 hrs and ovaries returned to normal, non-stimulated size by day 6 post-flushing. The majority of Sahiwal donors exhibited estrus within 9.90±1.06 days post-flushing. However, 70% of Sahiwal exhibited silent estrus. The mean interval from flushing to subsequent successful breeding was 29.86±5.24 days.