Role of the Central Nervous System in the Regulation of Pregnancy, Parturition and Lactation in Beef Heifers

dc.contributor.author Anderson, Lloyd
dc.date 2018-02-12T23:35:45.000
dc.date.accessioned 2020-06-29T23:49:44Z
dc.date.available 2020-06-29T23:49:44Z
dc.date.copyright Tue Jan 01 00:00:00 UTC 2002
dc.date.issued 2002-01-01
dc.description.abstract <p>Progesterone secretion is crucial for maintaining pregnancy to parturition in mammalian species, and in cattle the corpus luteum is the primary source of this hormone. This study determined the roles of prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH) in the luteotropic process in beef heifers hypophyseal stalk-transected (HST, n = 7) or sham operated on (SOC, n = 9) during midgestation. The main finding was that endogenous PRL and GH maintained progesterone secretion in HST heifers similar to that in SOC throughout pregnancy. Serum PRL averaged 37 vs 187 and GH 2 vs 4 ng/ml in HST compared with SOC, whereas LH abruptly decreased to undetectable levels after HST compared with a modest 0A4 ng/ml in SOC heifers. The second finding was that parturition and lactation occurred in HST heifers with calf delivery induced to occur at the same time as SOC. Milk production in HST animals was severely limited, and postpartum estrus obliterated compared with SOC. The suckling stimulus sustained milk ejection in HST heifers in spite of diminished PRL and GH secretion. The results suggest that PRL, GH and possibly placental lactogen are luteotropic during pregnancy in cattle.</p>
dc.format.mimetype PDF
dc.identifier archive/lib.dr.iastate.edu/beefreports_2001/36/
dc.identifier.articleid 1035
dc.identifier.contextkey 3183756
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath beefreports_2001/36
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/11056
dc.language.iso en
dc.relation.ispartofseries Animal Science Research Reports
dc.source.bitstream archive/lib.dr.iastate.edu/beefreports_2001/36/asl1770.pdf|||Fri Jan 14 23:46:02 UTC 2022
dc.subject.disciplines Animal Sciences
dc.subject.keywords ASL R1770
dc.title Role of the Central Nervous System in the Regulation of Pregnancy, Parturition and Lactation in Beef Heifers
dc.type article
dc.type.genre reproduction_and_physiology
dspace.entity.type Publication
relation.isSeriesOfPublication 7f3839b7-b833-4418-a6fa-adda2b23950a
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