Twelve growing Shami heifers available in Dier-Al-Hajar Station for
improving Shami Cattle weighing 115±3 kg and 178±4 days old were used to
determine the weekly hormonal concentrations of progesterone (P4) and
estradiol 17-β (E2) during the pre-
and puberty stages (6-14 mos). Blood
samples were collected weekly from the Jugular vein using vacutainer tubes
supported with K3EDTA.
Twelve growing Shami heifers available in Dier-Al-Hajar Station for
improving Shami Cattle weighing 115±3 kg and 178±4 days old were used to
monitor the daily growth of ovarian follicles (daily numbers, size, length and
number of waves, rate of gr
owth and regression) using Transrectal Ultrasound
Echo System (7.5 MHz probe) in 6-14 months-old heifers. Results indicated that
ovarian follicles developed in a wave pattern in all Shami heifers when they
were 6 months old and no significant differences in the number and size of
ovarian follicles were found between right and left ovaries. A cohort of 4 to 7
small follicles with a diameter 2-5 mm developed together and one of them was
selected for continual growth, became dominant and later regressed during the
pre-pubertal stage.
Thirteen viable and post - frozenthawed Shami cows embryos obtained by
super-ovulation and artificial insemination technique in order to determine sex
of embryos. Biopsies (1-2 cells) of embryos at morula or blastocyst stage were
taken using micro
manipulation under inverted microscope.
It was concluded that aspiration
of 1-2 blastomere (s) from embryos at morula or blastocyst stage was enough to
determine sex of embryo using PCR and it is recommended that using this
technique can be a useful tool in splitting and transferring of desired sex
embryos in genetic improvement program.
This research was conducted I during 2009-2010 at Dier Alhajar station,
General Commission for Scientific Agricultural Research to determine the
length of calving interval (CI) and the effect of sire, calving year, calving
season, parity and age o
f cow and their interactions in Shami Cattle.
It was concluded that CI can be reduced by better
management and providing good and suitable feeding conditions.
Twelve growing Shami heifers available in Dier-Al-Hajar Station for
improving Shami Cattle during 2005-2007 weighing 250±11 kg and 400±21
days old were used to monitore the growth of dynamic of ovarian follicles (daily
numbers, size, length and nu
mber of waves, rate of growth and regression) and
characteristics of estrus cycle (length, time of dominancy, diameter of Graffian
follicle and estrus and ovulatory times), length of corpus luteum (CL) during
the estrous cycle. Heifers were maintained under uniform conditions and fed
according to their daily growth. Transrectal Ultrasound Echo System (7.5 MHz
probe) was used to study the ovarian structures and to monitor the daily
development and regression of ovarian follicles, the formation and regression of
corpus luteum in the left and right ovaries during the estrus cycle. Results
indicated that the growth turnover of ovarian follicles was observed and
developed in a wave pattern in all Shami heifers and no significant differences
in the number and sizes of ovarian follicles were found between right and left
ovaries. A cohort of 5 to 7 small follicles with a diameter 2-5 mm developed
together and one of them was selected to continue growing and becomes
dominant and later on being regressed or ovulated during the estrus cycle. One
to five follicular waves were observed per cycle and each wave was
characterized by the development of one large (dominant) follicle and a
variable number of smaller follicles. The estrus cycle with one follicular wave
occurred only in heifers exhibited the first post pubertal cycles with an average
length equaled to 8.67±0.33 days. Frequency of estrus cycle according to the
number of follicular waves was 8.4, 25.3, 44.2, 20 and 2.1% in cycles having 1,
2, 3, 4 and 5 follicular waves, respectively. Furthermore , the length of estrus
cycle was also related to the number of follicular waves and it was 21.87±0.62,
22.44±0.74, 26.4±0.72, 26.50±3.50 days in cycles having 2, 3, 4 and 5 follicular
waves, respectively with significant differences (P < 0.05) in cycles with 2 or 3
vs. 4 and/or 5 waves. The functional duration of CL was extended to 9, 12 and
15 days in a short (17-19 days), intermediate (20-24 days) and long estrus cycle
(≥ 25 days). The maximum diameter of dominant follicles in ovulatory waves
was significantly larger (P < 0.05) than that of dominant follicles in nonovulatory
waves. In conclusion, this study showed that the development of
ovarian follicles in Shami heifers occurs in waves and the most common pattern
is three waves per estrous cycle.
This study conducted at Deir Al-Hajar Station during the season 2010-2011
to describe the lactation curve of Shami cattle and determine factors affecting
its shape compenents. 1120 records of 356 Shami cows collected between 1997 –
2010 were used.
Data were subjected to general linear model, and the analysis
of variance used to determine the effect of factors. Duncan test was used to
compare the means using SAS system (1996) and Incomplete gamma functions
were used to estimate the parameters of lactation curve (a, b and on the basis of
daily yield of milk.
Results indicated that the average values of the gamma parameters were
2.14 ± 0.01 kg for a (beginning of milking ), 0.61 ± 0.02 kg for b (increasing milk
production up to peak) and - 0.23± 0.01 kg for c (decreasing milk production
from peak to dry). The effect of calving year was significant (p<0.01) on a, and
(p<0.05) on b and (p<0.001) on c. The effect of age at calving and sex of calf was
significant (p<0.01) on a but non significant on b and c. Season of calving,
parity, and interaction between age and parity was not significant on all
parameters.
It was concluded that improving the productive performance of Shami
cattle, requires applying a long term genetic improvement program to select the
best herd.
Fifteen Shami cows available in Dier-Al-Hajar Station for improving Shami
Cattle were used during 2009-2010 to evaluate the ovarian response of cows for
gonadotropin releasing hormone (GnRH) or human chorionic gonadotropin
(hCG) injected on day 5
of the estrus cycle during which dominant follicle is
growing in the first follicular wave. Animals were divided randomly into three
groups of five cows. Group 1 was left as a control and received no treatment
while Groups 2 and 3 received on day 5 of the estrous cycle a single i.m.
injection of 8 ?g of a GnRH agonist (Buserelin) and 3000 IU hCG, respectively.
Transrectal ovarian ultrasonography was performed daily to monitor ovarian
follicular dynamics and corpus luteum.
This study was conducted at the Deir Al-Hajar Shami Cattle Research
Station, Animal Wealth Research Administration. For this purpose 12
primiparous Shami cows were used to know the influence of the milking
regimes in the production performance of
the cow and the composition of the
produced milk. The animals were divided randomly into two equal groups.
Machine milking were used at the first group in the presence of the calf, or for
the machine milking without the presence of the calf at the second group.
The daily production of milk was estimated weekly from every cow in both
groups and at the same time milk samples were taken to estimate the
percentage of the basic components of milk such as fat, protein, lactose and dry
matter until the end of lactation. Data were analyzed in statistical program SAS
by using variance analysis ANOVA (Mixed Model).
