CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Reproduction, Fertility and Development   
Reproduction, Fertility and Development
  Vertebrate reproductive science and technology
blank image Search
blank image blank image
blank image
  Advanced Search

Journal Home
About the Journal
Editorial Structure
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Virtual Issues
Sample Issue
For Authors
General Information
Submit Article
Author Instructions
Open Access
Awards and Prizes
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

blue arrow e-Alerts
blank image
Subscribe to our email Early Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter logo LinkedIn

red arrow Connect with SRB
blank image
facebook TwitterIcon

Affiliated Societies

RFD is the official journal of the International Embryo Transfer Society and the Society for Reproductive Biology.

Article << Previous     |     Next >>   Contents Vol 22(1)


J. R. V. Pimentel A, P. H. P. Miguez A, A. Kehrle A, E. H. Madureira A, F. A. Braga A, C. C. Rocha A and F. J. D. Pardo A

São Paulo University, Pirassununga, Brazil

Export Citation


Progestagen-releasing devices are commonly used for fixed-time artificial insemination and fixed-time embryo transfer (FTET). The aim of this study was to evaluate the efficacy of a new progesterone-releasing intravaginal device made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ε-caprolactone (PCL; Progestar®, Innovare, São Paulo, Brazil) to synchronize crossbredcows and heifers for FTET by determining ovulation, conception, and pregnancy rates. A total of 205 recipients ranging in age from 2 to 8 years (heifers, n = 77; non-suckled cows, n = 69; suckled cows, n = 59) were used on 3 different farms during February, March, and April 2008. The experimental design was a generalized block design (cyclicity, body condition score, postpartum interval, and animal category, i.e. heifers, suckled, or non-suckled cows), with 2 different synchronization treatments for FTET (Progestar® v. Crestar®). Cows were assigned to either Crestar® (norgestomet ear implants; Intervet Schering-Plough, Kenilworth, NJ, USA; n = 103) or Progestar® (PHB-V; n = 102) treatments. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal or auricular device according to their group (Day 0). Together with P4 device withdrawal (Day 8), all animals received 400 IU of eCG i.m. (Novormon®, Schering-Plough) and 500 μg i.m. of PGF2α, (Sincrocio®, Ouro Fino, Brasil). On Day 9, all cows were treated with 1 mg of estradiol benzoate (Innovare) and the innovulation was performed on Day 17. Embryos were maintained at 37°C during the innovulation period. The percentage of usable recipients (AR) based on the presence of a functional CL on the day of embryo transfer, conception rate (numbers of pregnant recipients of the total number transferred; CR), and pregnancy rate (numbers of pregnant recipients of the total number synchronized; PR) were determined by ultrasonography 23 days after embryo transfer. Data were submitted to ANOVA (PROC GLM, SAS Institute Inc., Cary, NC, USA) and significant differences were considered to have a P-value of <0.05. None of the interactions were significant and there was no effect of treatment on AR (72.8% v. 83.3%), CR (47.9% v. 42.7%), and PR (34.7% v. 35.0%) for Progestar® v. Crestar® groups, respectively. This experiment showed that Progestar® was as efficacious as Crestar® to synchronize crossbred cows and heifers for FTET.

FAPESP-Fundação de Amparo à Pesquisa do Estado de São Paulo and CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.

Reproduction, Fertility and Development 22(5305) 247–247   http://dx.doi.org/10.1071/RDv22n1Ab178
Published online: 08 December 2009

Top  Email this page

Legal & Privacy | Contact Us | Help


© CSIRO 1996-2016