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Two doses of prostaglandin improve pregnancy rates to timed-AI in a 5-day progesterone-based synchronization protocol in beef cows.
- Source :
-
Theriogenology [Theriogenology] 2009 Mar 15; Vol. 71 (5), pp. 762-7. Date of Electronic Publication: 2008 Nov 08. - Publication Year :
- 2009
-
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 100microg 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 (1xPGF; N=277), two 25mg doses of PGF, the first given on Day 5 at the time of CIDR removal and the second 7h later (2xPGF; N=282), or 500microg of CLP at the time of CIDR removal on Day 5 (1xCLP; N=271). All cows were given 100microg 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 2xPGF (69.0%) than the 1xPGF (52.0%) and 1xCLP (54.3%) treatments. However, breeding-season pregnancy rates were not different among treatments (87.0% for 1xPGF, 92.9% for 2xPGF and 87.5% for 1xCLP; 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.
- Subjects :
- Administration, Intravaginal
Animals
Body Composition
Breeding
Cloprostenol administration & dosage
Dinoprost administration & dosage
Female
Gonadotropin-Releasing Hormone administration & dosage
Insemination, Artificial methods
Male
Pregnancy
Prostaglandins F administration & dosage
Seasons
Cattle
Estrus Synchronization methods
Insemination, Artificial veterinary
Progesterone administration & dosage
Prostaglandins administration & dosage
Subjects
Details
- Language :
- English
- ISSN :
- 0093-691X
- Volume :
- 71
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Theriogenology
- Publication Type :
- Academic Journal
- Accession number :
- 18996581
- Full Text :
- https://doi.org/10.1016/j.theriogenology.2008.09.049