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dc.creatorRius, A. G.
dc.creatorAppuhamy, J. A. D. R. N.
dc.creatorCyriac, J.
dc.creatorKirovski, Danijela
dc.creatorBecvar, O.
dc.creatorEscobar, J.
dc.creatorMcGilliard, M. L.
dc.creatorBequette, B. J.
dc.creatorAkers, R. M.
dc.creatorHanigan, M. D.
dc.date.accessioned2020-06-03T13:21:39Z
dc.date.available2020-06-03T13:21:39Z
dc.date.issued2010
dc.identifier.issn0022-0302
dc.identifier.urihttp://vet-erinar.vet.bg.ac.rs/handle/123456789/711
dc.description.abstractThe objective of this study was to evaluate local molecular adaptations proposed to regulate protein synthesis in the mammary glands. It was hypothesized that AA and energy-yielding substrates independently regulate AA metabolism and protein synthesis in mammary glands by a combination of systemic and local mechanisms. Six primiparous mid-lactation Holstein cows with ruminal cannulas were randomly assigned to 4 treatment sequences in a replicated incomplete 4 x 4 Latin square design experiment. Treatments were abomasal infusions of casein and starch in a 2 x 2 factorial arrangement. All animals received the same basal diet (17.6% crude protein and 6.61 MJ of net energy for lactation/kg of DM) throughout the study. Cows were restricted to 70% of ad libitum intake and abomasally infused for 36 h with water, casein (0.86 kg/d), starch (2 kg/d), or a combination (2 kg/d starch + 0.86 kg/d casein) using peristaltic pumps. Milk yields and composition were assessed throughout the study. Arterial and venous plasma samples were collected every 20 min during the last 8 h of infusion to assess mammary uptake. Mammary biopsy samples were collected at the end of each infusion and assessed for the phosphorylation state of selected intracellular signaling molecules that regulate protein synthesis. Animals infused with casein had increased arterial concentrations of AA, increased mammary extraction of AA from plasma, either no change or a trend for reduced mammary AA clearance rates, and no change in milk protein yield. Animals infused with starch had increased milk and milk protein yields, increased mammary plasma flow, reduced arterial concentrations of AA, and increased mammary clearance rates and net uptake of some AA. Infusions of starch increased plasma concentrations of glucose, insulin, and insulin-like growth factor-I. Starch infusions increased phosphorylation of ribosomal protein S6 and endothelial nitric oxide synthase, consistent with changes in milk protein yields and plasma flow, respectively. Phosphorylation of the mammalian target of rapamycin was increased in response to starch only when casein was also infused. Thus, cell signaling molecules involved in the regulation of protein synthesis differentially responded to these nutritional stimuli. The hypothesized independent effects of casein and starch on animal metabolism and cell signaling were not observed, presumably because of the lack of a milk protein response to infused casein.en
dc.publisherElsevier Science Inc, New York
dc.relationCooperative State Research, Education and Extension Service, US Department of AgricultureUnited States Department of Agriculture (USDA)National Institute of Food and Agriculture [NC-1040]
dc.relationLand O' Lakes/Purina Feed LLC (Gray Summit, MO)
dc.relationVirginia State Dairymen's Association (Bridgewater, VA)
dc.rightsopenAccess
dc.sourceJournal of Dairy Science
dc.subjectaciden
dc.subjectcell signalingen
dc.subjectmammary glanden
dc.titleRegulation of protein synthesis in mammary glands of lactating dairy cows by starch and amino acidsen
dc.typearticle
dc.rights.licenseARR
dcterms.abstractЕсцобар, Ј.; Цyриац, Ј.; МцГиллиард, М. Л.; Беqуетте, Б. Ј.; Aкерс, Р. М.; Кировски, Данијела; Ханиган, М. Д.; Риус, A. Г.; Aппухамy, Ј. A. Д. Р. Н.; Бецвар, О.;
dc.citation.volume93
dc.citation.issue7
dc.citation.spage3114
dc.citation.epage3127
dc.citation.other93(7): 3114-3127
dc.citation.rankaM21
dc.identifier.wos000279026800031
dc.identifier.doi10.3168/jds.2009-2743
dc.identifier.pmid20630229
dc.identifier.scopus2-s2.0-77953897391
dc.identifier.fulltexthttp://veterinar.vet.bg.ac.rs/bitstream/id/1260/710.pdf
dc.identifier.rcubconv_1700
dc.type.versionpublishedVersion


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