MVSc

Literature available on the physiology of Japanese quail
is scanty. It is only in the recent years that any
concentrated attempt has been made to study the various
aspects of metabolism in domestic fowl. The present study was
undertaken to probe into some fundamental areas of
carbohydrate metabolism in Japanese quail with special
reference to the normal blood glucose level and liver glycogen
content of both sexes at various ages and physiological
conditions.
The study was carried out in four hundred and forty
Japanese quails (both sexes) of the same strain (egg type)
procured from Kerala Agricultural University Poultry Farm,
Mannuthy. In the first phase of study the estimations were
conducted in 40, zero day old (on the day of hatch) Japanese
quail chicks. In the second phase, 400, two week old quail
chicks were utilized. The males and females were separated at
four weeks of age and grouped into G1 (males) and G2 (females)
comprising of 20 birds in each subgroup. The birds were
maintained on standard quail rations in separate compartments
of the cage. Feed consumption was recorded at fortnightly
intervals. Twenty birds each from G1 (males) and G2 (females)
groups were sacrificed at fortnightly intervals from the

second to 16th week of age for the estimations. At the sixth
week of age two sets of males from G1 group (20+20) and
females from G2 group (20+20) were maintained on 50 per cent
feed restriction for a period of four weeks. At eighth (two
weeks feed restriction) and tenth (four weeks feed
restriction) week of age twenty birds each from control and 50
per cent feed restricted birds of G1 and G2 groups were
sacrificed for the different estimations as blood glucose
concentration, liver glycogen content, liver weight and body
weight.
The results from the study revealed that the highest
level of blood glucose was recorded at an age of zero day in
Japanese quail (244.425 ± 2.204) mg/dl). A decreasing
tendency in blood glucose level was observed as age advanced,
may be due to an increase in the erythrocyte count of adult
birds. In general female quails exhibited higher blood glucose
level than the male quails. The highest content of liver
glycogen (2.039 ± 0.102%) was recorded in the zero day. old
quail chicks (on the day of hatch). The level of glycogen
showed a decreasing tendency as age advanced, may be due to
the utilisation of liver glycogen for the energy requirements
of growing birds. There was no significant variation in liver
glycogen level due to sex. However there was higher liver
glycogen content in male quails at the age of two weeks.

Liver weight and body weight showed a tendency of steady
increase from the day of hatch to sixteenth week of age in
both sexes. The females had higher liver weight as well as
body weight than the males. The increase in liver weight may
be due to the increase in the number and size of liver cells
and also by excess deposits of energy required for growth.
The maximum body weight recorded at the age of 16 weeks in
both males and females were 170.500 ± 2.244 g and 184.000 ±
4.542 g respectively. Female quails had a higher body weight
than the male quails especially from sixth week of age
onwards, when they attained sexual maturity.
Two weeks feed restriction, did not influence the blood
glucose concentration and liver glycogen content in both sexes
of quails, whereas a significant reduction was noticed in the
liver weight and body weight of both male and female quails.
Four weeks feed restriction in male quails resulted in a
reduction in blood glucose level, liver glycogen content,
liver weight as well as body weight. However, in female
quails the blood glucose level and liver glycogen content were
not significantly altered, whereas body weight and liver
weight showed a significant reduction. The female quails were
able to withstand the situation by lowering the rate of egg
production.
Blood glucose concentration and liver glycogen content
exhibited a positive correlation in control as well as feed

restricted (Two weeks and four weeks) birds. However, there
was variation at different age levels in both male and female
quails. The mean liver weight and liver glycogen content in
both sexes of quails exhibited a negative correlation.
However, there was variation in the correlation due to sex and
age. Body weight and liver weight were found to be positively
correlated in both sexes of quails at all age periods and even
in feed restricted periods.
It was also observed that the daily feed consumption in
both male and female quails increased with the advancement of
age and female quails consumed more than the male quails.
Over and above the information obtained from the present
study on certain aspects of avian carbohydrate metabolism,
further studies are required to investigate the factors
influencing the regulation of normal levels of blood glucose
and liver glycogen in birds. The indefinite relation at
different age periods observed in Japanese quails between
blood glucose concentration and liver glycogen content and the
ability to withstand the changes in the levels of blood
glucose and liver glycogen, due to feed restriction, attract
further investigations. The factors involved may be either
the predominance of alpha cells in avian pancreas or role of
kidney in gluconeogenesis. It will also be interesting to
investigate the compensatory mechanisms that operate at the
time of feed restriction in the regulation of normal blood
glucose level and liver glycogen content.