Show simple item record

dc.contributor.authorCummins, Sean B*
dc.contributor.authorLonergan, P.*
dc.contributor.authorEvans, A.C.O.*
dc.contributor.authorButler, Stephen T.*
dc.date.accessioned2012-12-04T11:28:31Z
dc.date.available2013-12-12T10:33:06Z
dc.date.issued2012-07
dc.identifier.citationS.B. Cummins, P. Lonergan, A.C.O. Evans, S.T. Butler. Genetic merit for fertility traits in Holstein cows: II. Ovarian follicular and corpus luteum dynamics, reproductive hormones, and estrus behaviour. Journal of Dairy Science, 95(7), July 2012: 3698–3710. DOI: 10.3168/jds.2011-4976en_GB
dc.identifier.issn0022-0302
dc.identifier.urihttp://hdl.handle.net/11019/287
dc.descriptionPeer-revieweden_GB
dc.descriptionThis is the author’s version of a work that was accepted for publication in Journal of Dairy Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Dairy Science, volume 95 (7), July 2012
dc.description.abstractThe objective of this study was to characterize the estrous cycle of cows with similar proportions of Holstein genetics, similar genetic merit for milk production traits, but with good (Fert+) or poor (Fert-) genetic merit for fertility traits. A total of 37 lactating cows were enrolled on an 8-d CIDR-based protocol to synchronise estrus. 19 Fert+ and 12 Fert- cows that successfully ovulated a dominant follicle and established a corpus luteum underwent daily transrectal ultrasonography. Blood sampling was carried at 8 h intervals from d 0 to d 6 and from d 15 to ovulation, and once daily from d 7 to d 15. Blood samples were analysed for progesterone, estradiol, follicle stimulating hormone and luteinising hormone. Estrus behaviour was recorded using neck activity collars and mounting pads. Fert+ cows tended to have fewer (P = 0.07) follicular waves (2.2 vs. 2.7 waves) and had a shorter (P < 0.05) estrous cycle (21.0 vs. 25.1 d) than Fert- cows. There was no effect of genotype on day of first wave emergence or day of first wave dominant follicle peak diameter (all P > 0.05) but the peak diameter of the first wave dominant follicle tended to be larger (P = 0.08) in Fert- cows. During the first 13 d of the cycle, Fert+ cows developed a corpus luteum that was 16% larger (P = 0.08) than Fert- cows. Circulating progesterone concentrations were 34% greater (P < 0.001) in Fert+ than Fert- cows (5.15 vs. 3.84 ng/ml, respectively) from d 5 to d 13. During the final follicular wave, the interval from preovulatory follicle emergence to ovulation and the interval from preovulatory follicle dominance to ovulation were similar (P >0.05) in both genotypes. Maximum preovulatory follicle diameter was larger (P < 0.05) in Fert+ than Fert- cows (17.9 vs. 16.8 mm, respectively); however, circulating concentrations of oestradiol were not different (all P > 0.05) between genotypes. A greater proportion (P < 0.05) of Fert- cows ovulated to a silent heat than Fert+ cows (22% vs. 2%, respectively). Of cows that showed behavioural estrus Fert+ cows had 41% greater (P < 0.01) mean activity count; however, no difference (P > 0.05) was seen in mounting behaviour between genotypes. These results demonstrate for the first time that genetic merit for fertility has pronounced effects on corpus luteum development, progesterone concentration, preovulatory follicle diameter and behavioural estrus.en_GB
dc.language.isoenen_GB
dc.publisherAmerican Dairy Science Association and Elsevier Inc.en_GB
dc.relation.ispartofseriesJournal of Dairy Science;vol 95
dc.subjectgenetic merit for fertilityen_GB
dc.subjectreproductionen_GB
dc.subjectestrous cycleen_GB
dc.subjectprogesteroneen_GB
dc.titleGenetic merit for fertility traits in Holstein cows: II. Ovarian follicular and corpus luteum dynamics, reproductive hormones and estrus behaviouren_GB
dc.typeArticleen_GB
dc.embargo.terms2013-07-01en_GB
dc.identifier.rmis5672
dc.identifier.doihttp://dx.doi.org/10.3168/jds.2011-4976
dc.contributor.sponsorNational Development Plan (Dublin, Ireland)
dc.contributor.sponsorTeagasc Walsh Fellowship Programme
dc.contributor.sponsorDairy Levy Research Trust
refterms.dateFOA2018-01-12T07:42:59Z


Files in this item

Thumbnail
Name:
fertility_oestrouscycle_JDS_R2 ...
Size:
331.2Kb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record