الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
!S. SUMMARY
The present study was carried out at the sheep
experimental farm belonging to Animal Production Department,
Faculty of Agricalture, Zagazig University. Benha branch.
Hormonal assays were performed in the laboratories of
Endocrinology Research Unit, Radiobiology Department, Nuclear
Research Center, Atomic Energy Establishment, Enshas, Egypt.
It was planned to detect the hormonal pattern of thyroid
hormones (TB and T6) as well as sexual hormones (estradiol 17~
and progesterone) during different reproductive stages (estrous
cycle, pregnancy and 60 days of postpartum period). Ossimi
ewes and their cross with Rahmani of different parities
having single or twin embryos of different sexes (male,
female, and both male and femle embryos) were used in this
study. Total number of 21 and 18,21 and 20 , 24 and 21 Ossimi
and crossed ewes were subjected to the study during their
estrous cycle, pregnancy and 60 days after lambing,
respectively. Experimental period lasted from OCtober 1989 to
August, 1990.
Hormonal assays were carried out at the various stages
of the estrous cycle and up to the onset of the second
estrous (PrQestrus- estrus - meta estrus - Diestrus - second
estrus). As~ays were also carried out at 30 days intervals
during the regnancy period up to the 150th day as well as
during post artum period up to the 60th day.
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Results obtained could be summerized as follows
1- Hormonal pattern during estrous cycle:
A: Plasma thyrOid hormones level:
1- Plasma TI level showed significant (P<O.001) effect
due to parity number and significant (P<O.OS) due
to interaction between breed with parity number
while plasma T~ level showed significant effect
due to breed group, parity number, number of
embryoes and the linear regression on body weight
of ewe.
2- Higher value of plasma TI level was observed in
Oasimi ewes However, different trend showed in
plasma T~ level
3- Both the two thyroid hormones decreased as the
ewe’s parity increased with differnet rates in the
two hormones.
4- Ewes having twins had higher mean value of plasma
TI and T. level than those having single lamb.
S- Values of plasma T~ level showed greater variation
throughout the various stages of estrous cycle than
did the corresponding values of plasma TI.
B : Plasma estrogen and Progesterone levels:
1- Non of the factors studied had significant effect
on plasma estrogen level during estrous cycle
similer results were found in plasma progesterone
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level except the parity number and estrus stages.
2- Crossed ewes had the higher value of plasma
estrogen level while Ossimi ones had the higher
plasma progesterone level .
3- Ewe’s parity did not show similar effect in both
two sexual hormones.
4- Eewes having one Ovum had higher plasma level of
estrogen than those having two ova, plasma
progesterone level showed opposite results in the
aspect.
5- Plasma estrogen level showed insignificant
variation among the various stage of the estrous
cycle. Its consentration ranged from 75.55 pg/ml
in the diestrus period to 89.81 pg/ml in the
proestrus stage. The highest plasma progesterone
level (5.01 ng/ml) was found during the diestrus
stage, while it varied between 0.79 ng/ml during
the second estrus and 0.86 ng/ml during the
proestrus.
II Hormonal pattern during pregnancy:
A ; Thyroid hormones level in blood plasaa:
1- Plasma 1W level showed significant variation due
to all factors stUdied except ewe’s breed and the
interactions of breed X number of embryoes, breed
x periods, and parity x periods. However, plasma
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T. level showed significant variation due to
parity number, periods, breed x parity, breed x
number of embryoes and regression on weight of
ewes.
2- Crossbred ewes showed higher Ta mean (0.86 ng/ml)
than Ossimi ones (0.83 ng/ml). However the two
groups showed approximately similar mean of plasma
T. level.
3- Plasma thyroid hormones level decreased with
increasing ewe’s parity.
4- Ewes having male embryo showed the highest level
of plasma TI level which was approximately equal
to the corresponding value in ewes having female
embryo. Those having twins had the lowest level of
plasma TI. Quite different trend was found in the
plasma T. level. Ewes having male embryo had
plasma T. level intermediate in its magnitude
between ewes having female embryo and those of
twins.
5- Ewes having twins had higher values of both TI and
T. level in blood plasma when compared with those
having a single embryo with different magnitude.
6- No characteristic ·or similar trend was found
concerning the response of plasma Ta and Ttl levels
due to the pregnancy intervals. - ”’”-’_.
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B I Plasma level of estrogen and progesterone:
1- variation in plasma estrogen level during
pregnancy period was found to be of significant
value due to either periods, parity number,
interaction between parity x period, or type of
embryo x period. Plasma progesterone level showed
significnat variation due to period and
interaction of breed x type of embryo.
Crossbred ewes had higher level of estrogen
(323.34 pg/ml) and lower level of progesterone
(16.11 ng/ml) than Ossimi ones (311.29 pg/ml and
19.10 ng/ml respectively).
3- Ewes having male embryo had the highest
estrogen level than those having either
embryo or twins which had approximately similar
mean. Quite different results were
concerning the plasma progesterone level.
4- Plasma estrogen and progesterone levels were,
approximately, twice in ewes having twins than
those of a single embryo.
5- Plasma estrogen level increased as time of
pregnancy period passed reaching its maximum value
of 1120.90 pg/ml at the 150th day which was 25
folds higher than that value estimated at the 30th
day of pregnancy (45.87 pg/JDl).
2-
plasma
female
found
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Plasma progesterone level increased gradually and
steadely as pregnancy time passed reaching its
maximum (35.09 ng/ml) level at the 120th days then
decreased during the last 30 days reaching a value
of 18.14 ng/ml-
III Hormonal attern durin the
A- Plasma thyroid hormones level:
1- Plasma TI level showed significant variation due
to factors studied ( except ewe’s breed , parity
number and Breed x sex of lamb, Breed x period and
between parity x period interactions) However, the
significnat variations (P<O.OOl) were found in
case of T. level due to the breed x parity, Breed
x sex of lamb interactions and due to regression
on weight of ewe.
2- Crossbred ewes had slightely higher means of both
the two hormones than the Ossimi ones.
3- The two hormone levels decreased as ewe’S parity
increased.
4- Plasma TI level decreased as time after
parturition passed reaching its lowest level at
the 60th day after lambing. Plasma T. level
decreased up to the 30th day after lambing then
increased up to the 60th day reaching a level,
approximately similar to that found at lambing
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day.
B : Plasma level of estrogen and progesterone:
1- Non of the factors studied had significant effect
on plasma estrogen and progesterone levels.
2- Crossbred ewes had relatively higher mean values
of either estrogen or progesterone levels than
Ossimi ones.
3- Estrogen level in plasma incresed as number of
ewe’s parity increased lowest mean of plasma
progesteroue was found in ewes having two
parities.
4- Ewes having female lambs showed the lowest level
of both plasma estrogen and progesterone levels
compared with those ewes having male lambs or ewes
having twins •
5- Plasma levels of both estrogen and progesterone
increased as time after lambing passed with
greater rate in case of estrogen than
progesterone.