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Effects of Prepartum Energy and Protein Density on Productivity and Influence of Dietary Iron on Copper Status of Holstein and Jersey Cattle

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dc.contributor.authorFrench, Patrick Douglasen
dc.contributor.committeechairJames, Robert E.en
dc.contributor.committeememberPolan, Carl E.en
dc.contributor.committeememberSwecker, William S. Jr.en
dc.contributor.committeememberStallings, Charles C.en
dc.contributor.committeememberMcGilliard, Michael L.en
dc.contributor.departmentAnimal and Poultry Sciencesen
dc.date.accessioned2014-03-14T21:23:15Zen
dc.date.adate1999-04-11en
dc.date.available2014-03-14T21:23:15Zen
dc.date.issued1999-08-16en
dc.date.rdate2000-04-11en
dc.date.sdate1999-11-29en
dc.description.abstractIn experiment 1, 24 multiparous Holsteins and 24 multiparous Jerseys were assigned at random to one of four diets containing either 1.25, 1.38, 1.50, or 1.63 Mcal NEL/kg DM to determine the effects of prepartum energy density on productivity. Cows were assigned to diets 28 d before expected calving and received a similar diet 0 to 60 d postpartum. Prepartum DMI increased linearly as dietary energy density increased. Non-esterified fatty acids did not differ for energy density and were greater for Holsteins. Milk and 4% FCM increased linearly as dietary energy density increased, although postpartum DMI was quadratic for energy density. Fat yield increased linearly with energy density and protein yield did not differ. Increasing prepartum diet energy density increased yield of milk and 4% FCM. In experiment 2, 26 multiparous and 18 primiparous Jerseys were assigned to one of two CP and rumen undegradable protein (RUP) concentrations 30 d before expected calving to determine the effects of CP and RUP on productivity. Cows received a similar diet 0 to 60 d postpartum. Prepartum CP concentrations were 12 and 15% and prepartum RUP (% of CP) concentrations were 30 and 45%. Dry matter intake was not affected by CP or RUP. Milk yield and 4% FCM yield did not differ for CP or RUP. In addition, milk protein concentration and yield were similar for CP and RUP. Positive calculated metabolizable protein balance for 12% CP and 30% RUP concentrations may have precluded responses to increasing prepartum CP and RUP. In experiment 3, 12 Holstein and 12 Jersey multiparous cows were assigned at random to diets containing 0 or 500 mg FeCO3/kg DM to investigate the effects of dietary Fe on milk production and Cu status. Hepatic Cu did not differ for breeds or Fe supplementation. For Jerseys, hepatic Fe was greater for cows receiving supplemental Fe. Hepatic Zn was similar for breed and Fe supplementation. Plasma Cu was greater for Jerseys compared to Holsteins and did not differ for Fe supplementation. Plasma Fe and Zn did not differ for breeds or Fe supplementation. Iron supplementation did not affect yield of milk or 4% FCM. Dietary Fe did not affect Cu status of Holstein and Jersey cows in this experiment.en
dc.description.degreePh. D.en
dc.identifier.otheretd-112999-031257en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-112999-031257/en
dc.identifier.urihttp://hdl.handle.net/10919/40376en
dc.publisherVirginia Techen
dc.relation.haspartetd.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectProteinen
dc.subjectEnergyen
dc.subjectPrepartumen
dc.subjectDry Matter Intakeen
dc.subjectCopperen
dc.titleEffects of Prepartum Energy and Protein Density on Productivity and Influence of Dietary Iron on Copper Status of Holstein and Jersey Cattleen
dc.typeDissertationen
thesis.degree.disciplineAnimal and Poultry Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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