Journal article
Two doses of prostaglandin improve pregnancy rates to timed-AI in a 5-day progesterone-based synchronization protocol in beef cows
Theriogenology, Vol.71(5), pp.762-767
03/15/2009
Handle:
https://hdl.handle.net/2376/103074
PMID: 18996581
Abstract
The objective was to compare reproductive performance of Angus-cross beef cows synchronized with GnRH, a progesterone-based intravaginal insert (Controlled Internal Drug Release, CIDR) for 5-d, and one dose of either dinoprost (PGF) or cloprostenol (CLP, a PGF analogue) or two doses of PGF on the day of CIDR withdrawal. All cows (N=830) at six locations received 100μg of GnRH and a CIDR on Day 0. Within farm, cows were randomly allocated to receive 25mg of PGF at the time of CIDR insert removal on Day 5 (1×PGF; N=277), two 25mg doses of PGF, the first given on Day 5 at the time of CIDR removal and the second 7h later (2×PGF; N=282), or 500μg of CLP at the time of CIDR removal on Day 5 (1×CLP; N=271). All cows were given 100μg of GnRH on Day 8 (72h after CIDR removal) and concurrently inseminated (5-d CO-Synch+CIDR). Cows were fitted with a pressure-sensitive estrus detection device at the time of CIDR withdrawal. Timed-AI pregnancy rates were greater (P<0.0001) in the 2×PGF (69.0%) than the 1×PGF (52.0%) and 1×CLP (54.3%) treatments. However, breeding-season pregnancy rates were not different among treatments (87.0% for 1×PGF, 92.9% for 2×PGF and 87.5% for 1×CLP; P>0.1). In conclusion, cows that received two doses of PGF on the day of CIDR removal in a 5-d CO-Synch+CIDR synchronization protocol had excellent timed-AI pregnancy rates that were greater than in cows receiving a single treatment with either PGF or CLP.
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Details
- Title
- Two doses of prostaglandin improve pregnancy rates to timed-AI in a 5-day progesterone-based synchronization protocol in beef cows
- Creators
- R Kasimanickam - Department of Large Animal Clinical Sciences, Virginia Maryland Regional College of Veterinary Medicine, Duckpond drive, Phase II, Blacksburg, VA 24061, USAM.L Day - Department of Animal Sciences, College of Food, Agricultural, and Environmental Sciences, Columbus, OH 43210, USAJ.S Rudolph - Department of Large Animal Clinical Sciences, Virginia Maryland Regional College of Veterinary Medicine, Duckpond drive, Phase II, Blacksburg, VA 24061, USAJ.B Hall - Department of Animal and Poultry Science, College of Agricultural and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USAW.D Whittier - Department of Large Animal Clinical Sciences, Virginia Maryland Regional College of Veterinary Medicine, Duckpond drive, Phase II, Blacksburg, VA 24061, USA
- Publication Details
- Theriogenology, Vol.71(5), pp.762-767
- Academic Unit
- Veterinary Clinical Sciences, Department of
- Publisher
- Elsevier Inc
- Identifiers
- 99900546674801842
- Language
- English
- Resource Type
- Journal article