PhD

Poultry products are comparatively rich in cholesterol. WHO report indicates
incidence of coronary heart disease and high dietary cholesterol level to be positively
correlated. In such a situation, decreasing the cholesterol content in poultry products would be
appropriate.
Onion and garlic are ascribed with therapeutic effects such as hypocholesterolemia,
hypolipidemia and immunosuppressant action in mammals, while no convincing reports are
available on the effect of supplementation of these agents in reducing cholesterol level in egg
and poultry meat. Hence, this study reports on the hypolipidemic effects and/or other effects
of dietary onion and garlic on the lipid profile in the tissues of Japanese quails.
Further, information on the physiological norms of tissues is essential for
understanding any pathological entity. Although in recent years, the Japanese quail has
gained increasing popularity as a biological model for various investigations, published
reports on the lipid profile in the tissues of this species are very few. Essentially, all the
previous studies on this aspect are based on observations in only a particular tissue or a
particular lipid component or sex and age.
Hence, the present investigation is also aimed at establishing a more or less complete
picture of lipid profile in liver, plasma and muscle in both sexes at three different
physiological stages of growth viz., three-week old (immature), six-week old (onset of sexual
maturity) and in nine-week old (mature) birds. Likewise, the lipid profile that are analysed in
the liver will also be: established in the egg yolk.
The results revealed an increase in the liver and plasma total lipid content (Table II)
due to onion and garlic. Although a trend of decrease in the cholesterol level in the liver and
muscle was observed the results were statistically nonsignificant (Table III), indicating the
hypocholesterolemic effect of onion and garlic to be of questionable biological significance.


The plasma free cholesterol level (Table IV) was found to be decreased due to onion
and garlic, while no effect of the same was observed with regard to plasma esterified cholesterol
(Table IV). The effect of onion and garlic on the cholesterol content in different lipoproteins
(Table IV) indicated that these alliums are causing recirculation of plasma cholesterol between
different lipoproteins and/or tissues in such a way that the plasma LDL-C is not increased.
There was an increase in the triglyceride content in the liver and plasma due to dietary
alliums (Table V). The phospholipid level in the plasma was found to be increased with a
decrease in the plasma free fatty acid (Table XII) level due to dietary alliums. The variations
in the plasma esterified fatty acid content (Table XII) due to alliums are in accordance with the
variations in the plasma content of esterified form of lipids. The iodine value of liver lipid was
increased due to alliums in both sexes, while these alliums were found to have no influence on
the saponification and acid value of the liver lipid.
In all the above instances where onion and garlic were found to have significant effect,
dietary garlic was found to have either a similar or significantly more alliaceous effect than
dietary onion.
No significant variations in the lipid profile of the muscle and yolk were observed due
to dietary supplementation of onion and garlic.
The influence of onion and garlic on the feed consumption by birds was found to vary
with duration of feeding. In the first week of feeding alliums to both sexes and in the second
week in the male birds, no change in the feed consumption was observed. Thereafter in both
the sexes the feed consumption increased due to dietary onion and garlic. Dietary onion and
garlic caused a nonsignificant increase in the body weight. Feed efficiency in both the sexes and
egg production in the females were unaltered due to dietary supplementation of onion and
garlic.







The levels of total lipid, total cholesterol, triglycerides, total phospholipid and
phospholipid fractions in liver, plasma and muscle were found to differ significantly due to
effect of age within a sex and due to effect of sex within an age group. Similarly the level of
plasma free cholesterol, esterified cholesterol, HDL-C, VLDL-C, HDL-C, free fatty acid and
esterified fatty acid differed significantly due to age within a sex and due to sex within an age
group. Iodine value and saponification value of lipid in liver were influenced due to age and
sex, while the same was not observed in the muscle. The acid value of the lipid in the liver
and muscle was unaltered due to age or sex. The feed consumption and body weight
increased with age in both sexes and it was more in the females. The feed efficiency was
unaltered due to age or sex. The egg production was also not influenced by age.