Effect of 5-aminolevulinic acid on immune response, rumen fermentation and milk production in dairy cows

概要

（別紙様式

14）
2020 年

3月

6日

論文の内容の要約
氏

名

Amin Omar Hendawy Masoud

学位の種類

博士（農学）

学府又は研究科・専攻

連合農学研究科

指導を受けた大学

東京農工大学

学位論文名

Effect of 5- aminolevulinic acid on immune response,
rumen fermentation and milk production in dairy cows

生物生産科学専攻

【論文の内容の要約】

Introduction: 5-Aminolevulinic acid (5-ALA) is a naturally occurring amino acid,
which plays an important role in the biosynthesis of heme. This study was conducted
with the aim of examining the effect of 5-aminolevulinic acid (5-ALA) as a dietary
supplement on milk yield and immune response in lactating dairy cows as well as
rumen fermentation, and the composition of ruminal microbes in vivo and in vitro.
Methods: This cross over study used two periods, 12 days for adaptation with a test
period of 2 days where lactating Holstein cows (n= 6-13) were randomly assigned to a
control group that was fed a total mixed ration (TMR) only and to a treatment group,
which received a TMR supplemented with 10 mg 5-ALA/kg of feed. In vitro study,
rumen samples from 2 dairy cows were incubated with 5-ALA, protoporphyrin IX, and
cyanocobalamin. In addition, in vitro incubation culture of peripheral blood
mononuclear cells (PBMC) was conducted in order to examine the possible mechanism
underlying immunomodulation by 5-ALA.
Results: 5-ALA improved milk protein and milk casein contents, which was associated
with improvements in total volatile fatty acids (VFA) concentration in the rumen fluid
as a result of change in microbiota composition: increase of total bacteria and
Succinivibrio dextrinsolovens by supplementation of 5-ALA. Dairy cows fed 5-ALA
supplemented diet exhibited increase in mitogen-induced proliferation of PBMC than in
cows fed basal diet. 5-ALA caused a significant decrease in the expression of tumor
necrosis factor-α (TNF-α) mRNA in PBMC. 5-ALA improved and alleviated the
inflammatory response stimulated with Lipopolysaccharide of E.coli by inhibiting the
expression of TNF-α mRNA, while the expression level of TNF-α was slightly
increased with 5-ALA supplementation in absence of LPS stimulation as compared with
control cultures.