R. Derar
Assiut University
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Featured researches published by R. Derar.
Reproduction in Domestic Animals | 2009
A. Ali; A. Kh. Abdel-Razek; R. Derar; Ha Abdel-Rheem; Sh Shehata
The objective of this study was to investigate the common forms of reproductive disorders and trends of fertility in cattle and buffaloes in Middle Egypt, and investigate nutritional deficiencies or imbalances as a cause of infertility. During the period from 2003 to 2006 a total of 4276 animals (2755 cattle and 1521 buffaloes) were examined, during winter and summer at three districts of Middle Egypt. Based on the owner complains, animals were categorized as anestrum, repeat breeder and those for pregnancy diagnosis. Feedstuffs of these districts were assessed for nutrient and mineral contents. Animals were examined by rectal palpation and by transrectal ultrasonography. The results showed that, ovarian inactivity was the most common cause of anestrum, whereas endometritis was the main frequent finding of repeat breeding. District, season and year affected the incidences of infertility. The pregnancy rate remained constant (cattle) or increased (buffaloes) from 2003 to 2006. The incidence of ovarian inactivity in both species decreased over the same period. In winter, the commonly used feedstuffs would be adequate to supply the animals with needs, but in summer, rations seem to be deficient in many essential nutrients. In conclusion, ovarian inactivity is the main cause of infertility in cattle and buffaloes in Middle Egypt. There is a link between poor nutrition in summer and the high incidence of ovarian inactivity. Fertility trends during the past few years are encouraging.
Animal Reproduction Science | 2013
Taymour M. El-Sherry; R. Derar; R. Bakry
The aim of the present study was to examine the relation between follicular blood flow of the ovulatory follicle and the levels of serum E2 and nitric oxide (NO) in Ossimi ewe. Seven cyclic ewes were synchronized with a double injection PGF2α. The follicular wave was examined daily until ovulation (disappearance of the large dominant follicle ultrasonographically) with transrectal color Doppler ultrasonography (8-10MHz linear array transducer). The number of recruited follicles was 4.8±0.9 (3-8 follicles) with diameter of 2.8±0.1mm. The interval from PGF2α injection to follicle deviation was 2.35±0.07 days. The diameter of the first largest follicle (LF1) at recruitment day was 4±0.3mm while the diameter of the second largest follicle (LF2) was 3.7±0.1mm. The diameter of LF1 at the day of deviation was 5.1±0.5mm while the diameter of the LF2 was 4±0.7mm. The diameter of the ovulatory follicle was 6.1±0.5at day of ovulation. We detected the blood flow area of the ovulatory follicle at D2. At ovulation, the blood flow area and blood flow area percent increased significantly to be 11.9±0.6mm(2) and 44±3.4% respectively. The results showed a positive correlation between E2 and NO (r=0.85, P<0.009). Both increased concomitantly with the diameter of the ovulatory follicle. Besides, NO and E2 reached a maximum level at ovulation (12.1±1.8ng/ml and 16.4±1.7pg/ml respectively).
Animal Reproduction Science | 2011
A. Ali; R. Derar; H. A. Hussein; M. R. Abd Ellah; A. Kh. Abdel-Razek
The aim of this study was to investigate uterine torsion in buffaloes, examine factors influencing the outcome of the disease, and to characterize the related alterations in blood constituents. A total of 126 buffaloes with uterine torsion were examined for stage of gestation, duration, degree, site and direction of torsion, as well as the location of the pregnant horn. Methods of correction were documented along with dam and calf survival. Blood samples were obtained from 20 buffaloes with uterine torsion and 10 healthy buffaloes for hematological and biochemical comparisons. Results showed that uterine torsion in buffaloes occurred in multi- (81.7%) and primiparous (18.3%), during late pregnancy (58.4%) and at full term (41.6%), clockwise (96%) and counter- clockwise (4%), at post- (98.4%) and precervical (1.6%), and was of high (52.3%), moderate (31%) and mild (16.7%) degrees. Torsion was predominantly (P=0.01) on same direction of the pregnant horn. Fetal and maternal mortalities occurred in 78.6% and 23.8% of the cases, respectively. The stage of pregnancy, and degree and duration of uterine torsion were major risk factors for fetal mortality (P=0.0001), while the stage of pregnancy and fetal viability were important risk factors for maternal mortality (P<0.05). There were significant (P<0.05) increases in monocytes, albumin, aspartate aminotransferase, creatine phosphokinase, blood urea nitrogen, and phosphorus and decreases in mean corpuscular hemoglobin concentration and globulin in the affected buffaloes. Time of occurrence and duration of torsion affected some of these parameters. Uterine torsion appears to be a serious problem in buffaloes that has certain peculiarities including time of occurrence, site and direction of torsion, and the high mortality rates. Uterine torsion adversely affects liver and kidney functions. Multiparous might be at greater risk of uterine torsion. The stage of pregnancy, as well as degree and duration of uterine torsion are risk factors for fetal and maternal mortalities.
Animal Reproduction Science | 2014
Mohamed Sadawy Rawy; R. Derar; Taymour M. El-Sherry; Gaber Megahed
The objectives of this study were to investigate the ovarian follicular waves and their corresponding hormonal changes in she-camels and to elucidate blood perfusion of the ovarian structures. Three reproductively sound, non-pregnant female camels were examined daily using B-mode and color Doppler to detect changes in their ovarian structures and blood vasculature for 22 follicular waves. Blood area (BA) and percentage (BA%) were determined for the ovarian structures. Three phases of follicular development, those of growth, maturation, and regression, were observed during each follicular wave. Deviation occurred on Day 6.1±1.08. Estradiol increased from basal levels of 27.4±0.4pg/ml to peak concentrations of 134.4±47.5pg/ml as the follicle reached a diameter of 13.2mm. Peripheral progesterone concentrations remained low (<0.4ng/ml) throughout the follicular waves. The blood flow to the dominant follicles increased gradually with follicular growth. The BA and BA% reached the maximum values of 18.4±11.6mm(2) and 6.04±2.03%, respectively, when the diameter of the dominant follicle was 17.5±3.4mm. The blood flow to the corpus luteum rose markedly after ovulation to reach a maximum BA% and BA at Days 5 and 7, respectively, post ovulation. In conclusion, the follicular wave pattern in dromedaries consists of individually variable periods of growth, maturation and regression. Deviation occurs 6.1±1.08d from emergence. Transrectal color-Doppler sonography is a useful technique for noninvasive evaluation of follicular vascularity in camels during various stages of the follicular wave. It provides additional information to assess the developmental stage and activity of the ovarian structures.
Animal Reproduction Science | 2014
R. Derar; A. A. Ali; Fahd Al-Sobayil
The aim of the present study was to investigate the time for complete uterine involution and resumption of ovarian activity in postpartum dromedary camels, relative to hormonal changes. A total of six females were examined by ultrasonography twice weekly starting 3d after parturition. GnRH was administered when the follicles reached ≥0.9cm diameter. Blood samples were collected for hormonal analysis. Results revealed that the mean intervals for complete involution of the previously gravid horn, non-gravid horn, and cervix were 34.33±3.9, 29.01±0.81, and 28.71±1.51d, respectively. After GnRH treatment (Days 17-34), five of the six camels had ovulated. The corpus luteum was detected by Day 4.1±1.6 after GnRH treatment and lasted for 6±1.1d. Serum progesterone (P4) was basal and increased only after GnRH treatment. Serum estradiol 17-β (E2) peaked twice: when a large follicle was detected and 8.5±2.8d post-GnRH treatment. The serum FSH pattern was biphasic, with two peaks just before the recruitment of small follicles and 4.67±4.1d after GnRH treatment. The five ovulating females were mated; two conceived after the first service and three after the second service. The interval from calving to conception was 78.16±3.71d. It was concluded that in dromedary camels, involution of the uterus is completed by the 5th week postpartum, these camels are highly responsive to early GnRH treatment, and they can be mated between the 5th and 6th week after parturition with encouraging conception rates.
Veterinary Medicine International | 2011
R. Derar; H. A. Hussein
The objective of the current study was to describe follicular dynamics in Egyptian Jennies throughout the estrous cycle. In this experiment, 8 estrus cycles in 8 cyclic Jennies were studied from February to June using ultrasonography. The result revealed that one follicular wave per cycle was recorded throughout the studied period. Dominant follicle (DF) was firstly detected at −0.80 ± 0.84 day in Jennies. The growth rate of DF was 2.32 ± 0.18 mm/day. Left ovulations were nonsignificantly (P = .07) more than right ovulations (55.6% versus 44.6%). The CL was firstly detected at D 2.58 ± 1.2, developed in a rate of 1.19 ± 0.07 mm/day, reached a maximum diameter of 30.77 ± 1.28 mm at D 13.0 ± 0.70, and started to regress on D 17.05 ± 0.64 with a mean regression rate of 1.75 ± 0.17 mm d−1. Results of the present study indicated that Jennies had one follicular wave per cycle. The Day of the cycle has a significant effect on the number of different classes of the ovarian follicles, but not large ones. Ultrasonographic characteristics of the preovulatory follicles could be useful to predict ovulation. CL developed and regressed in a slow rate.
Theriogenology | 2015
A. A. Ali; R. Derar; Fahd Al-Sobayil; A. Al-Hawas; Khaled M. A. Hassanein
The objective of this study was to investigate the clinical findings in barren female dromedaries examined for different complaints. Female camels were examined for repeat breeding with regular heat interval (RB-R, n = 5444), refused mating (RM, n = 1299), repeat breeding with long heat interval (RB-L, n = 489), difficulties or bleeding during mating (DM, n = 53), and for manifestation of male-like behavior (MB, n = 15). The genital tracts of all females were evaluated using transrectal palpation, ultrasonography, and exploration of the vagina. Cervical swabs were obtained for bacteriologic examination. Clinical endometritis, ovarian hydrobursitis, and vaginal adhesions were the main clinical findings in the female camels examined for RB-R, RM, and RB-L, respectively. Parity affected the frequency of occurrence of these findings. The incidences of clinical endometritis, ovarian hydrobursitis, and vaginal adhesions in nullipara and multipara were 28% versus 32.3% (P = 0.004), 37.1% versus 23.7% (P = 0.001), and 5.7% versus 18.3% (P = 0.001), respectively. Vaginal adhesions, persistent hymen, pelvic abscess, and vulvar atresia were the clinical findings in the female camels presented due to bleeding at mating or with a history of an incomplete intromission of the penis. The male-like behavior was associated with an enlargement of the clitoris and narrowing of the vulva and vagina. Trueperella pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Streptococcus zooepidemicus, and β-hemolytic Streptococcus were isolated from females presented for repeat breeding syndrome. In conclusion, clinical endometritis, ovarian hydrobursitis, and vaginal adhesions were the main clinical findings in barren female dromedaries. Parity affected the frequency of the clinical findings.
Journal of Applied Animal Research | 2013
M. R. Abd Ellah; Maha I. Hamed; R. Derar
The current study aimed to establish reference values for pregnant Egyptian buffaloes (Bubalus bubalis) during the second trimester of pregnancy. All animals included in the study were non-lactating. The International Federation of Clinical Chemistry stated that at least 120 values were necessary to obtain reliable estimates for reference values. A total number of 134 clinically healthy midterm pregnant (3.5–7.0 months) buffaloes (3–8 years old) were included in this study. Animals were examined at the buffalo farms that belonged to the Assiut Governorate in the middle of Egypt. Three types of samples were collected: serum samples for biochemical analysis, whole blood samples for haematological analysis and faecal samples for parasitological examination. Animals that fit the inclusion criteria were included in this study. Biochemical analysis included serum total proteins, albumin, total globulins, α-, β- and γ-globulin levels, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, creatine phosphokinase and lactate dehydrogenase activities, serum creatinine, blood urea nitrogen, total bilirubin, direct bilirubin, indirect bilirubin, sodium, potassium, chloride, magnesium, calcium, phosphorus, copper, zinc, iron, triglycerides, high-density lipoprotein, low-density lipoprotein, very low density lipoprotein and glucose levels. In addition, 20 haematological variables were measured. The 95% reference intervals were calculated by removing the upper and lower 2.5% of the intervals for each serum biochemical constituent to give 2.5 and 97.5 percentiles. Confidence intervals were calculated for each reference limit. Reference values from the current study were compared with the established values for cows. The current study is the first study to established reference values for the blood biochemical and haematological constituents in non-lactating buffaloes during the second trimester of pregnancy.
Animal Reproduction Science | 2009
A. Ali; M. Hayder; R. Derar
The present study was carried out to assess the reproductive performance of Farafra ewes--a breed with potential economic importance in the subtropics. A total of 262 ewes were categorized according to age, parity, and postpartum interval. Ewes were introduced for breeding in fall, winter and late spring seasons. Fertility, prolificacy, lamb birth weight, and ultrasonic fetal parameters were recorded. Results obtained showed that litter size was increased with age and parity. Lamb birth weight was affected by season. None of the parameters studied had a clear-cut effect on fertility. However, an interaction between season and parity was detected. Measurement of fetal size in the first half of gestation did not predict birth weight. The obtained data represents the first record of the reproductive performance of Farafra ewes in the subtropics, which could be used to anticipate their performance in different seasons.
Theriogenology | 2006
A. Ali; R. Derar; H. A. Hussein
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Obihiro University of Agriculture and Veterinary Medicine
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