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9THE USE OF ECG TO INCREASE PREGNANCY RATES IN POSTPARTUM BEEF COWS FOLLOWING TREATMENT WITH PROGESTERONE VAGINAL DEVICES AND ESTRADIOL BENZOATE AND FIXED-TIME AI
- Source :
- Reproduction, Fertility and Development. 16:127
- Publication Year :
- 2004
- Publisher :
- CSIRO Publishing, 2004.
-
Abstract
- Treatments with progesterone (P4) releasing devices and estradiol benzoate (EB) have been extensively used in fixed-time AI (FTAI) programs in beef cattle. However, pregnancy rates in postpartum cows kept on pasture often have been lower than expected because of poor body condition score (BCS) and a high incidence of anestrous. A recent study (Cutaia L et al., 2003 Theriogenology 59, 216) suggested that the addition of eCG to a P4/EB FTAI program may improve pregnancy rates in cows with fair to poor BCS, but results were not conclusive. Therefore, this experiment was designed to further investigate the effect of eCG treatment on pregnancy rates in postpartum beef cows in those conditions. The experiment was performed at 2 locations with lactating Angus cows (n=93), 60 to 90d postpartum with a BCS 1.9 (1 to 5 scale; Location 1), and crossbred Zebu cows (n=290), 60 to 90d postpartum with a BCS 2.0 (Location 2). In each Location, cows were randomly allocated to 1 of the following treatment groups: Control, eCG Day6, or eCG Day8. All cows received a P4 intravaginal device (DIB, Syntex, Argentina) and 2mg EB i.m. (Syntex) on Day0, 500mg cloprostenol (Estroplan, Syntex) at the time of DIB removal (Day8), 1mg EB i.m. on Day9 and FTAI 52 to 56h after DIB removal. Cows in the Control group received no further treatment, whereas cows in the eCG-treated groups received 400 IU eCG (Novormon 5000, Syntex) on Day6 or Day8. Cows were examined on Day0 by rectal palpation (Location 1) or by ultrasonography (US; Location 2) and were classified as those with a CL or without a CL, with either large (>8mm) or small (
- Subjects :
- medicine.medical_specialty
Pregnancy
Semen
Reproductive technology
Beef cattle
Biology
medicine.disease
Zebu
chemistry.chemical_compound
Endocrinology
medicine.anatomical_structure
Animal science
Reproductive Medicine
chemistry
Lactation
Internal medicine
Genetics
medicine
Estradiol benzoate
Animal Science and Zoology
Folliculogenesis
Molecular Biology
Developmental Biology
Biotechnology
Subjects
Details
- ISSN :
- 10313613
- Volume :
- 16
- Database :
- OpenAIRE
- Journal :
- Reproduction, Fertility and Development
- Accession number :
- edsair.doi...........506b0e48bfd1512291238697b4395b83