Material Type  

 학위논문

 

0016930933

Date and Time of Latest Transaction  

20240214095837

ISBN  

9798379744984

DDC  

636

Author  

Monteiro, Hugo Fernando.

Title/Author  

Using Live Microorganisms to Modulate Ruminal Fermentation - [electronic resource]

Publish Info  

[S.l.] : University of Florida., 2021

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2021

Material Info  

1 online resource(177 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 84-12, Section: B.

General Note  

Advisor: Faciola, Antonio.

학위논문주기  

Thesis (Ph.D.)--University of Florida, 2021.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Abstracts/Etc  

요약Live microorganisms have been used as feed additives to cattle in order to strategically change the ruminal microbial community dynamics, thus, improving ruminal fermentation and animal performance. The objective of this dissertation was to evaluate different situations that live microorganisms could be used in order to modulate ruminal fermentation. The focus of this work was on ruminal fermentation; therefore, different experimental models were used to understand the mechanism of action of the microorganisms used across studies.In chapter 2, the goal was to evaluate how silage treated with lactic acid bacteria (LAB; Lactobacillus plantarum MTD/1) inoculants could improve ruminal fermentation and milk production in high-producing dairy cows. Dry matter intake, nutrient digestibility, and milk production increased in cows receiveing the treated silage, despite of minor changes in energy-corrected milk (ECM). The increase in ruminal nutrient digestibility were not followed by improvements in ruminal N metabolism, which may explain the lack of responses in ECM.In chapters 3 and 4, the LAB L. plantarum GB-LP1 was tested as direct fed microbials (DFM) on ruminal fermentation of high-producing dairy cow diets. In a series of in vitro studies, the inclusion rate in the diet and the mode of action of the LAB of focus was investigated in comparison with a mix of LAB and lactic acid utilizing bacteria (MLP). All DFM tested in the study improved ruminal N metabolism by negatively affecting some fibrolytic bacterial genera that may dispose proteolytic activity; changes were mostly associated to the fluid phase.In chapter 5, the focus of the study was to create an acute ruminal acidosis scenario in vitro by using a dual-flow continuous culture system, and to feed a mix of lactic acid utilizing bacteria and yeast as DFM in order to ameliorate acidosis. Yeast was tested in this study in combinations with two new strains of Megasphaera eldesnii isolated from the rumen of acidotically challenged beef cattle. Acute ruminal acidosis was successfully induced in vitro; however, the DFM in the study were not able to reduce the acid load or improve ruminal fermentation. Therefore, in chapter 6, a literature review about ruminal acidosis is presented in order to investigate potential factors besides the acid load in the rumen that could explain the ruminal problems seen from this digestive disorder.

Subject Added Entry-Topical Term  

Animal sciences.

Subject Added Entry-Topical Term  

Microbiology.

Subject Added Entry-Topical Term  

Agriculture.

Index Term-Uncontrolled  

Beef-cattle

Index Term-Uncontrolled  

Dairy-cow

Index Term-Uncontrolled  

Lactobacillus-plantarum

Index Term-Uncontrolled  

Megasphaera-elsdenii

Index Term-Uncontrolled  

Rumen

Index Term-Uncontrolled  

Saccharomyces-cerevisiae

Added Entry-Corporate Name  

University of Florida Animal Sciences

Host Item Entry  

Dissertations Abstracts International. 84-12B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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소장사항  

202402 2024

Control Number  

joongbu:639836