Factors Affecting Synchronization and Conception Rate after the Ovsynch Protocol in Lactating Holstein Cows
- 18 May 2010
- journal article
- Published by Wiley in Reproduction in Domestic Animals
- Vol. 45 (3), 439-446
- https://doi.org/10.1111/j.1439-0531.2008.01220.x
Abstract
Objectives were to evaluate risk factors affecting ovulatory responses and conception rate to the Ovsynch protocol. Holstein cows, 466, were submitted to the Ovsynch protocol [day 0, GnRH-1; day 7, prostaglandin (PG) F(2alpha); day 9, GnRH-2] and 103 cows were inseminated 12 h after GnRH-2. Information on parity, days in milk at GnRH-1, body condition, milk yield, exposure to heat stress, pre-synchronization with PGF(2alpha) and the use of progesterone insert from GnRH-1 to PGF(2alpha) was collected. Ovaries were scanned to determine responses to treatments. Overall, 54.7%, 10.6%, 2.2%, 81.1%, 9.0%, 91.5% and 36.9% of the cows ovulated to GnRH-1, multiple ovulated to GnRH-1, ovulated before GnRH-2, ovulated to GnRH-2, multiple ovulated to GnRH-2, experienced corpus luteum (CL) regression and conceived, respectively. Ovulation to GnRH-1 was greater in cows without a CL at GnRH-1, cows with follicles >19 mm and cows not pre-synchronized with PGF(2alpha) 14 days before GnRH-1. Multiple ovulations to GnRH-1 increased in cows without CL at GnRH-1 and cows with follicles < or =19 mm at GnRH-1. Ovulation before GnRH-2 was greater in cows without CL at PGF(2alpha). Ovulation to GnRH-2 increased in cows that received a progesterone insert, cows with a CL at GnRH-1, cows with follicles not regressing from the PGF(2alpha) to GnRH-2, cows with larger follicles at GnRH-2, cows that ovulated to GnRH-1 and cows not pre-synchronized. Multiple ovulations after GnRH-2 increased in cows with no CL at GnRH-1, multiparous cows and cows that multiple ovulated to GnRH-1. Conception rate at 42 days after AI increased in cows with body condition score > 2.75 and cows that ovulated to GnRH-2. Strategies that optimize ovulation to GnRH-2, such as increased ovulation to GnRH-1, should improve response to the Ovsynch protocol.Keywords
This publication has 29 references indexed in Scilit:
- Reducing the Interval from Presynchronization to Initiation of Timed Artificial Insemination Improves Fertility in Dairy CowsJournal of Dairy Science, 2007
- Survey of Management Practices on Reproductive Performance of Dairy Cattle on Large US Commercial FarmsJournal of Dairy Science, 2006
- Reproduction in Dairy Cows Following Progesterone Insert Presynchronization and Resynchronization ProtocolsJournal of Dairy Science, 2006
- Optimizing Ovulation to First GnRH Improved Outcomes to Each Hormonal Injection of Ovsynch in Lactating Dairy CowsJournal of Dairy Science, 2006
- Effect of addition of a progesterone intravaginal insert to a timed insemination protocol using estradiol cypionate on ovulation rate, pregnancy rate, and late embryonic loss in lactating dairy cows1Journal of Animal Science, 2004
- Pregnancy in Dairy Cows After Synchronized Ovulation Regimens With or Without Presynchronization and ProgesteroneJournal of Dairy Science, 2004
- Follicular Size and Response to Ovsynch Versus Detection of Estrus in Anovular and Ovular Lactating Dairy CowsJournal of Dairy Science, 2003
- Stage of Cycle, Incidence, and Timing of Ovulation, and Pregnancy Rates in Dairy Cattle after Three Timed Breeding ProtocolsJournal of Dairy Science, 2001
- Effect of milk production on the incidence of double ovulation in dairy cowsTheriogenology, 1999
- Principal Descriptors of Body Condition Score in Holstein CowsJournal of Dairy Science, 1994