| Resynchronization strategies to improve fertility in lactating dairy cows utilizing a presynchronization injection of GnRH or supplemental progesterone: I. Pregnancy rates and ovarian responses. | |
| | |
MedLine Citation:
|
PMID: 20723683 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Objectives were to evaluate 3 resynchronization protocols for lactating dairy cows. At 32+/-3 d after pre-enrollment artificial insemination (AI; study d -7), 1 wk before pregnancy diagnosis, cows from 2 farms were enrolled and randomly assigned to 1 of 3 resynchronization protocols after balancing for parity, days in milk, and number of previous AI. All cows were examined for pregnancy at 39+/-3 d after pre-enrollment AI (study d 0). Cows enrolled as controls (n=386) diagnosed not pregnant were submitted to a resynchronization protocol (d 0-GnRH, d 7-PGF2alpha, and d 10-GnRH and AI) on the same day. Cows enrolled in the GGPG (GnRH-GnRH-PGF2alpha-GnRH) treatment (n=357) received a GnRH injection at enrollment (d -7) and if diagnosed not pregnant were submitted to the resynchronization protocol for control cows on d 0. Cows enrolled in CIDR treatment (n=316) diagnosed not pregnant received the resynchronization protocol described for control cows with addition of a controlled internal drug release (CIDR) insert containing progesterone (P4) from d 0 to 7. In a subgroup of cows, ovaries were scanned and blood was sampled for P4 concentration on d 0 and 7. After resynchronized AI, cows were diagnosed for pregnancy at 39+/-3 and 67+/-3 d (California herds) or 120+/-3 d (Arizona herds). Cows in the GGPG treatment had more corpora lutea than CIDR and control cows on d 0 (1.30+/-0.11, 1.05+/-0.11, and 1.05+/-0.11, respectively) and d 7 (1.41+/-0.14, 0.97+/-0.13, and 1.03+/-0.14, respectively). A greater percentage of GGPG cows ovulated to GnRH given on d 0 compared with CIDR and control cows (48.4, 29.6, and 36.6%, respectively), but CIDR and control did not differ. At 39+/-3 d after resynchronized AI, pregnancy per AI (P/AI) was increased in GGPG (33.6%) and CIDR (31.3%) cows compared with control (24.6%) cows. At 67 or 120+/-3 d after resynchronized AI, P/AI of GGPG and CIDR cows was increased compared with control cows (31.2, 29.5, and 22.1%, respectively). Presynchronizing the estrous cycle of lactating dairy cows with a GnRH 7 d before the start of the resynchronization protocol or use of a CIDR insert within the resynchronization protocol resulted in greater P/AI after resynchronized AI compared with control cows. |
| | |
Authors:
|
S T Dewey; L G D Mendonça; G Lopes; F A Rivera; F Guagnini; R C Chebel; T R Bilby |
Related Documents
:
|
8236703 - Effects of gonadotrophin releasing hormone administered 11 days after insemination on t... 16725633 - Possible "immuno-protection" of the bovine parvovirus in the uterus: preliminary commun... 9074223 - Pregnancy after laparoscopic myomectomy |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Journal of dairy science Volume: 93 ISSN: 1525-3198 ISO Abbreviation: J. Dairy Sci. Publication Date: 2010 Sep |
Date Detail:
|
Created Date: 2010-08-20 Completed Date: 2010-11-30 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 2985126R Medline TA: J Dairy Sci Country: United States |
Other Details:
|
Languages: eng Pagination: 4086-95 Citation Subset: IM |
Copyright Information:
|
Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved. |
Affiliation:
|
University of Arizona, Department of Animal Sciences, Tucson 85721, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Abortion, Veterinary
/
physiopathology Animals Cattle Estrus Synchronization / methods*, physiology Female Gonadotropin-Releasing Hormone / blood, pharmacology* Insemination, Artificial / methods, veterinary Lactation / physiology Milk / secretion Ovary / drug effects*, ultrasonography Parity Pregnancy Pregnancy Rate Progesterone / blood, pharmacology* |
| Chemical | |
Reg. No./Substance:
|
33515-09-2/Gonadotropin-Releasing Hormone; 57-83-0/Progesterone |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Effects of 2.1 and 3.5x10(6) sex-sorted sperm dosages on conception rates of Holstein cows and heife...
Next Document: Evaluation of a biological risk management tool on large western United States dairies.