الفهرس 
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Abstract
This work was carried out on 600 wister albino rats, 300 syrian hamsters and 200 English guinea pigs to investigate the behaviours of these animals and the best possible methods of management •.
1- Rat and hamster neonates were born rosy red in color
with a sealed fingers, ears and eyes. In rat the hairs
was present only in vibres’sae and above each eye while
in hamster the body was covered with a very fine hairs
in addition to the hairs of vibrissae. Incisors were
present only in hamster while it was absent in rat.
The young guinea pig were born fully furred, with
open ears and eyes, erupted incisors, separated fingers
and obvious 2 teats.
2- Averages of litter sizes were 7.26 ± 0.31, 8.14 ± 0.43
and 2.44 ± 0.2 while the sex ratios (% of males % of
females) were 48.58 .. 51.42, 53.45 •. 46.55 and 33.87 :
66.13 . The birth weights were 5.49 ± 0.09, 2.66 ± 0.06
and 74.24 ± 0.53 for males and 5.34 ± 0.09, 2.50 ± 0.05
62.21 ± 0.04 for females in rat, hamster and guinea pig
respectively.
3- Fostering of orphan youngs was successfully performed
between dams of the same species but failed when
performed between different species.
4- In rat the age of pUberty was affected by sex, litter
size and the period of light.
In hamster the age of puberty was not affected by sex
or the period of light in both sexes while the litter size
affected male but not female.
Puberty in guinea pig was not affected by sex, litter
size or the period of light.
5- The age of maturity of females was 70.54 ± 1.34, 50.13
± 1.18, 53.67 ± 1.62 and 92.75 ± 1.71 days in rat,
hamster and guinea pig respectively.
6- The oestrus cycle1enqth was 4.38 ± 0.01, 4 and 16.67 ±
0.72 days in f-.ales rat, baaster and guinea pig
respectively.
When these aniJals were reared in continuous ligbt
the oestrus cycle lentth was 6.23 ± 0.44, 4.59 + 0.08 and
17.78 ± 0.49 day. r••••ctively. Th. incr•••• in the cycle
length was significant only in case of females rat. When
these females were caged together away from males, the
oestrus cycle length was 4.61 ± 0.08, 4 and 16.62 ± 0.49
days respectively. Absence of males prolonged the cycle
length by a significant value in case of female rats only,
while it is not affected in case of females hamsters and
guinea pigs. If the youngs were died during nursing period
the first oestrus was obtained after 2.82±0.49, 4.25±O.93
and l5.00±6.26 days from the day of death in rats,hamsters
and guinea pigs respectively. post-parturient oestrus was
occurred after 1.6±O.55 days from the time of partruition
in case of rats and after 1.97± 0.09 hour in case of sows,
it is not observed in case of hamsters.
8- Averages of gestation periods were 22.04 ± 0.12, 15.4 ±
0.15 and 67.05 ± 0.50 days in rat, hamster and guinea
pig respectively.
9- No abortion was observed in rat and hamster while 8
cases of abortion were recorded in guinea pig.
10- The number of teats were 12, 13-15 and 2 in rat,
hamster and guinea pig respectively.
11- Pregnancy could be diagnosed in rat by vaginal smear,
vaginal plug, absence of oestrus, abdominal palpation,
weighing and increase in the abdominal size.
In hamster it could be expected by vaginal smear,
vaginal plug, absence of post-ovulatory discharge, change
in the character of the vaginal discharge, abdominal
palpation, weighing and increase in the abdominal size.
Pregnancy could be confirmed in
plug, abdominal palpation, •weighing
abdominal size.
12- A perfod of hibernation was observed in hamster during
winter season. In this period the oestrus was stopped,
the testes and scent glands were atrophied and a
complete adhesion between the glans penis and prepuce
was observed. Increasing the period of illumination
can not restore the activity of the gonads, while a
temperature of 22-25•C could do that. Also breeding
was stopped in rats when reared on a wire mesh cages,
while continued in that group which reared on a solid
bottom cages with a bedding material. The breeding
performance was not influenced by seasonal variations
in guinea pig.
13-from the elements of maternal behaviour which exhibited
by female rat and hamster, licking, retrieving, nest
building and nursing, while the dam guinea pig showed
licking and nursing only, so maternal behaviour was
higher in rat and hamster than guinea pig.
14- productive females whether pregnant or lactating
ingested more food and water than aaintainant ones.
15- The body weight of the pregnant feaales ~iately
after partruition was higher than that at day 0 of
pregnancy.
16- Lactation increalJlidthe weight of nursing rat, while
decreased that of hamster and guinea pig.
The body weight ofyo~ng rat, guinea pig and males of
hamster exhibited• a reverse relationship with the
litter size, female hamster was not affected. Young
males were heavier than females in rat and guinea pig,
but nearly of the same weight in hamster.
17- Birth weight in guinea pig was in a direct relation
with the viability of the young, but in a reverse
relation with the litter size.
18- Anogenita1 distance at birth in rat and hamster was
3.7 and 2 rom in males, while it was 1.5 and 1 mm in
females respectivelY.