Please use this identifier to cite or link to this item: http://hdl.handle.net/1843/32623
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dc.contributor.advisor1Ronaldo Braga Reispt_BR
dc.contributor.advisor1LattesCV: http://lattes.cnpq.br/2333068453228104pt_BR
dc.contributor.advisor-co1Shawn S. Donkinpt_BR
dc.creatorVictor Marco Rocha Malaccopt_BR
dc.creator.Latteshttp://lattes.cnpq.br/7997498583508161pt_BR
dc.date.accessioned2020-02-28T12:40:35Z-
dc.date.available2021-01-21T11:11:04Z-
dc.date.issued2019-12-13-
dc.identifier.urihttp://hdl.handle.net/1843/32623-
dc.description.resumoThe guiding hypothesis explored in this dissertation is that the value of rumen-protected lysine (RP-Lys) is a function of its stability when premixed in feeds, inertness in the rumen, post ruminal bioavailability, and impact on production parameters when fed to lactating dairy cows. A second hypothesis tested was that lysine and energy supply act to regulate genes that are critical for lysine catabolism in bovine. To test these hypotheses, four related studies were performed. The studies evaluated the rumen-protected Lys product stability, bioavailability and lactating dairy cow’s performance due to its use as a supplement in Lys deficient corn-based diets and determined the effects of extracellular Lys levels and energy supply on aminoadipate-semialdehyde synthase (AASS) mRNA expression as an indicator of a gene specific to Lys catabolism. Overall, summarizing all those studies related to the RP-Lys we conclude that association of the storage practices before feeding RP-Lys and the low bioavailability observed in the bioavailability trial might result in a lower delivery than predicted for digestible Lys in the small intestine resulting in a lack of response in the lactation trial. In addition, multiple AA may have been limiting when most of the dietary protein was derived from corn products which could also dampen the expected increase in plasma Lys and increase of milk yield and milk components. The increase in the Lys in the media and providing an additional energy source did not translate in alterations in the AASS expression and confirms data from in vivo studies with increased postruminal lysine supply. Taken together, the information presented in this thesis highlights the importance of maintaining the integrity of the protection technology for RP-Lys through all sequential segments leading to postruminal presence of free lysine.pt_BR
dc.description.sponsorshipCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorpt_BR
dc.languageengpt_BR
dc.publisherUniversidade Federal de Minas Geraispt_BR
dc.publisher.countryBrasilpt_BR
dc.publisher.departmentVET - DEPARTAMENTO DE ZOOTECNIApt_BR
dc.publisher.programPrograma de Pós-Graduação em Zootecniapt_BR
dc.publisher.initialsUFMGpt_BR
dc.rightsAcesso Restritopt_BR
dc.subjectAminoácidospt_BR
dc.subjectproteínapt_BR
dc.subjectProdução Animalpt_BR
dc.subject.otherZootecniapt_BR
dc.titleRumen-protected lysine for dairy cows: stability, bioavailability and lactation performancept_BR
dc.typeTesept_BR
dc.description.embargo2020-12-13-
Appears in Collections:Teses de Doutorado



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