Ovarian characteristics, serum hormone concentrations, and fertility in lactating dairy cows in response to equine chorionic gonadotropin

K-REx Repository

Show simple item record

dc.contributor.author Pulley, Stephanie Leeann
dc.contributor.author Wallace, L.D.
dc.contributor.author Mellieon, H.I.
dc.contributor.author Stevenson, Jeffrey S.
dc.date.accessioned 2012-09-07T15:44:09Z
dc.date.available 2012-09-07T15:44:09Z
dc.date.issued 2012-09-07
dc.identifier.uri http://hdl.handle.net/2097/14657
dc.description Dairy Research, 2010 is known as Dairy Day, 2010 en_US
dc.description.abstract The objective of this study was to evaluate the effects of equine chorionic gonadotropin (eCG) on various characteristics associated with an effective timed artificial insemination (AI) protocol in lactating dairy cows. Cows (n = 121) in a single herd were treated with 2 injections of prostaglandin F2α (PGF2α) 14 days apart (Presynch), with the second injection administered 11 days before the onset of a timed AI protocol. Cows received either saline or 400 IU eCG concurrent with the PGF2α injection of the Ovsynch protocol (injection of gonadotropinreleasing hormone or GnRH, 7 days before and 48 to 56 hours after PGF2α with insemination occurring 12 to 16 hours after the second GnRH injection). Blood samples were collected during the study to monitor serum changes in progesterone and estradiol in order to determine if eCG would facilitate increased estrual activity, improved ovulatory response, and enhanced postovulatory luteal function. Administration of eCG tended to increase the number of corpora lutea (CL) and on days 9 and 16 after PGF2α, corresponding to days 6 and 13 postovulation, but the volume of the luteal tissue was less than that in the control. Timed AI pregnancy rates did not differ between eCG (36.9%) and control cows (41.8%). We concluded that use of eCG provided no profertility advantages to dairy cattle when programmed for a timed insemination at first service. en_US
dc.publisher Kansas Agricultural Experiment Station and Cooperative Extension Service en_US
dc.relation.isPartOf Dairy Day, 2010 en_US
dc.relation.isPartOf Kansas Agricultural Experiment Station contribution; no. 11-129-S en_US
dc.relation.isPartOf Report of progress (Kansas Agricultural Experiment Station and Cooperative Extension Service); 1039 en_US
dc.subject Dairy en_US
dc.subject Corpus luteum en_US
dc.subject Equine chorionic gonadotropin en_US
dc.subject Follicle en_US
dc.subject Progesterone en_US
dc.subject timed artificial insemination (AI) en_US
dc.title Ovarian characteristics, serum hormone concentrations, and fertility in lactating dairy cows in response to equine chorionic gonadotropin en_US
dc.type Conference paper en_US
dc.date.published 2010 en_US
dc.citation.epage 21 en_US
dc.citation.spage 19 en_US
dc.description.conference Dairy Day, 2010, Kansas State University, Manhattan, KS, 2010
dc.contributor.authoreid jss en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search K-REx

Advanced Search


My Account


Center for the

Advancement of Digital


118 Hale Library

Manhattan KS 66506

(785) 532-7444