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Updated: Jun 26, 2026
09:30
In Vitro Culture Strategy for Oocytes from Early Antral Follicle in Cattle
Published on: July 8, 2020
Factors affecting synchronization and conception rate after the Ovsynch protocol in lactating Holstein cows
1Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. kag73@cornell.edu
Reproduction in Domestic Animals = Zuchthygiene
|January 16, 2009
Summary
This study identified key factors influencing ovulatory responses and conception rates in Holstein cows undergoing the Ovsynch protocol. Optimizing ovulation to GnRH-2, particularly by enhancing ovulation to GnRH-1, is crucial for improving overall reproductive efficiency in cattle.
Area of Science:
- Reproductive endocrinology in cattle
- Artificial insemination protocols
- Dairy cattle management
Background:
- The Ovsynch protocol is widely used for timed artificial insemination in cattle.
- Understanding factors affecting its efficacy is vital for improving reproductive performance.
- Ovulatory response and conception rates are critical outcomes of synchronization protocols.
Purpose of the Study:
- To evaluate risk factors impacting ovulatory responses to the Ovsynch protocol.
- To identify factors influencing conception rates following the Ovsynch protocol.
- To provide insights for optimizing cattle reproductive efficiency.
Main Methods:
- 466 Holstein cows were subjected to the Ovsynch protocol (GnRH-1, PGF(2alpha), GnRH-2).
- Data collected included parity, days in milk, body condition, milk yield, heat stress, pre-synchronization, and progesterone insert use.
- Ovarian activity was monitored via ultrasound to assess ovulation and corpus luteum (CL) dynamics.
Main Results:
- Ovulation to GnRH-1 was influenced by CL presence, follicle size, and pre-synchronization.
- Ovulation to GnRH-2 was enhanced by progesterone insert use, CL presence, follicle size, and prior ovulation to GnRH-1.
- Conception rate was positively associated with body condition score and ovulation to GnRH-2.
Conclusions:
- Factors such as CL status, follicle size, and progesterone supplementation significantly affect ovulatory responses.
- Improving ovulation to GnRH-1 and GnRH-2 is key to enhancing the success of the Ovsynch protocol.
- Optimizing the Ovsynch protocol through management strategies can improve conception rates in dairy cows.
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