Ovarian follicular dynamics and pregnancy outcomes of Thai swamp buffaloes (<i>Bubalus bubalis</i>) submitted to ovulation-synchronization protocol with different timing of insemination.
Inseminating Thai swamp buffaloes 72 hours after P4-device removal improves pregnancy rates compared to 96 hours.
Where it sits
this study against the rest of the teriparatide (pth 1-34) corpusSummary and findings
This study investigated follicular dynamics and pregnancy outcomes in Thai swamp buffaloes using an ovulation-synchronization protocol. Buffaloes were inseminated at either 72 or 96 hours after P4-device removal. A higher pregnancy rate was observed at 72 hours post-removal.
Abstract
Experiments were conducted to investigate follicular dynamics and timing of ovulation in Thai swamp buffaloes (<i>Bubalus bubalis</i>) and compare the pregnancy rate in buffaloes submitted to the 11-day progesterone (P4)-prostaglandin F<sub>2α</sub> (PGF<sub>2α</sub>)-equine chorionic gonadotrophin (eCG)-gonadotropin-releasing hormone (GnRH)-based protocol with different timing of insemination. In experiment 1, follicular dynamics and timing of ovulation were determined from buffaloes receiving P4-device insert from Days 0 to 11, PGF<sub>2α</sub> and eCG on Day 11, and GnRH at 48 h after P4-device removal. In experiment 2, the pregnancy rate was compared between buffaloes that were inseminated either at 72 or 96 h after P4-device removal. Ovulatory buffaloes had a greater growth rate of the dominant follicle from Day 11 to 48 h after P4-device withdrawal compared with anovulatory buffaloes (1.2 ± 0.10 vs. 0.8 ± 0.11 mm/day). The peak level of luteinizing hormone (LH) showed an increase in ovulatory buffaloes compared with anovulatory buffaloes (4.8 ± 0.46 vs. 2.5 ± 0.15 mIU/mL). The interval between P4-device removal and LH peak was shorter in ovulatory buffaloes compared to anovulatory buffaloes (79.2 ± 5.11 vs. 116.4 ± 14.54 h). The majority of the buffaloes ovulated 96 h after P4-device withdrawal (75.0%). Inseminating buffaloes 72 h after P4-device removal yielded a higher pregnancy rate than when buffaloes were inseminated 96 h after P4-device removal (71.4 vs. 44.4%). It is concluded that an optimal pregnancy rate can be achieved when Thai swamp buffaloes are bred artificially 72 h after P4-device removal, following ovulation-synchronization with the 11-day P4-PGF<sub>2α</sub>-eCG-GnRH-based protocol.
Background
The study addresses the optimization of artificial insemination timing in Thai swamp buffaloes using an ovulation-synchronization protocol. Previous research has shown the importance of timing in achieving successful pregnancy rates in livestock. This study is relevant as it seeks to improve reproductive efficiency in buffaloes, which is crucial for agricultural productivity.
Methods
The study involved two experiments with Thai swamp buffaloes. In experiment 1, follicular dynamics were monitored following a protocol involving an 11-day P4-device, PGF2α, eCG, and GnRH. In experiment 2, pregnancy rates were compared between buffaloes inseminated at 72 or 96 hours after P4-device removal. The primary outcome was the pregnancy rate, while secondary outcomes included follicular growth and hormone levels.
Results
The primary finding was that inseminating buffaloes 72 hours after P4-device removal resulted in a higher pregnancy rate of 71.4% compared to 44.4% at 96 hours. Ovulatory buffaloes showed a greater growth rate of the dominant follicle (1.2 ± 0.10 mm/day) and higher peak LH levels (4.8 ± 0.46 mIU/mL) compared to anovulatory buffaloes. The interval to the LH peak was shorter in ovulatory buffaloes.
Interpretation
The results suggest that timing insemination at 72 hours post P4-device removal is more effective for achieving higher pregnancy rates in Thai swamp buffaloes. While the findings are statistically significant, their clinical significance is limited to this specific breed and protocol. The study's applicability to other breeds or species remains uncertain, and the findings should be interpreted with caution.
Key findings
- 1.2 ± 0.10 mm/day growth rate of dominant follicle in ovulatory buffaloes.
- 4.8 ± 0.46 mIU/mL peak LH level in ovulatory buffaloes.
- 79.2 ± 5.11 hours interval to LH peak in ovulatory buffaloes.
- 75.0% of buffaloes ovulated 96 hours after P4-device withdrawal.
- 71.4% pregnancy rate at 72 hours post P4-device removal.
Limitations
- Limited to Thai swamp buffaloes.
- Single species study.
- Specific to the 11-day P4-PGF2α-eCG-GnRH protocol.