Document Detail

Resynchronization with unknown pregnancy status using progestin-based timed artificial insemination protocol in beef cattle.
MedLine Citation:
PMID:  24139935     Owner:  NLM     Status:  Publisher    
Two experiments were designed to evaluate the use of resynchronization (RESYNCH) protocols using a progestin-based timed artificial insemination (TAI) protocol in beef cattle. In experiment 1, 475 cyclic Nelore heifers were resynchronized 22 days after the first TAI using two different inducers of new follicular wave emergence (estradiol benzoate [EB; n = 241] or GnRH [n = 234]) with the insertion of a norgestomet ear implant. At ear implant removal (7 days later), a pregnancy test was performed, and nonpregnant heifers received a dose of prostaglandin plus 0.5 mg of estradiol cypionate, with a timed insemination 48 hours later. The pregnancy rate after the first TAI was similar (P = 0.97) between treatments (EB [41.9%] vs. GnRH [41.5%]). However, EB-treated heifers (49.3%) had a greater (P = 0.04) pregnancy per AI (P/AI) after the resynchronization than the GnRH-treated heifers (37.2%). In experiment 2, the pregnancy loss in 664 zebu females (344 nonlactating cows and 320 cyclic heifers) between 30 and 60 days after resynchronization was evaluated. Females were randomly assigned to one of two groups (RESYNCH 22 days after the first TAI [n = 317] or submitted only to natural mating [NM; n = 347]). Females from the NM group were maintained with bulls from 15 to 30 days after the first TAI. The RESYNC-treated females were resynchronized 22 days after the first TAI using 1 mg of EB on the first day of the resynchronization, similar to experiment 1. No difference was found in P/AI (NM [57.1%] vs. RESYNC [61.5%]; P = 0.32) or pregnancy loss (NM [2.0%] vs. RESYNC [4.1%]; P = 0.21) after the first TAI. Moreover, the overall P/AI after the RESYNCH protocol was 47.5%. Thus, the administration of 1 mg of EB on day 22 after the first TAI, when the pregnancy status was undetermined, promotes a higher P/AI in the resynchronized TAI than the use of GnRH. Also, the administration of 1 mg of EB 22 days after the TAI did not affect the preestablished pregnancy.
M F Sá Filho; M O Marques; R Girotto; F A Santos; R V Sala; J P Barbuio; P S Baruselli
Related Documents :
24925815 - Pup retrieval and maternal attraction to canine amniotic fluids.
22229095 - Folic acid and birth defects: a case study (iran).
18203075 - Successful pregnancy in a uremic patient treated with single needle hemodialysis.
22355075 - Deregulation of gene expression induced by environmental tobacco smoke exposure in preg...
11194545 - Successful exit (ex utero intrapartum treatment) procedure in a fetus diagnosed prenata...
24375775 - Early detection of severe brain lesions after fetoscopic laser treatment in twin-twin t...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-9-28
Journal Detail:
Title:  Theriogenology     Volume:  -     ISSN:  1879-3231     ISO Abbreviation:  Theriogenology     Publication Date:  2013 Sep 
Date Detail:
Created Date:  2013-10-21     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0421510     Medline TA:  Theriogenology     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2013 Elsevier Inc. All rights reserved.
Departamento de Reprodução Animal, FMVZ/USP, São Paulo, SP, Brazil. Electronic address:
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effect of ovarian tissue vitrification method on mice preantral follicular development and gene expr...
Next Document:  The effect of interleukin-1?, interleukin-6, and tumor necrosis factor-? on estradiol-17? release in...