[Show abstract][Hide abstract]ABSTRACT: The objective of this study was to evaluate efficacy of diagnostic techniques of endometritis in Arabian mares. An ultrasonographic evaluation as well as cytological and bacteriological examinations of uterine swabs have been performed in Arabian mares (n=43) suffered from endometritis. Mares showed a highly significant (P<0.001) impact of age on the occurrence of various grades of endometritis, with the occurrence of severe grade (E4) in mares elder than 18 years. The mean number of neutrophils in the cytological examination of endometrial swabs was 3.79±0.22, 4.90±0.32, 6.50±0.65 and 9.66±0.33 in E1, E2, E3 and E4, respectively (p<0.001). There was a highly significant (P<0.0001) difference in the echogenicity of the inflammatory fluid and endometrial wall and the diameter of uterine horn and lumen among different grades endometritis. The overall incidence of single and mixed bacterial infection in mares endometritis was 67.35% and 30.23 %, respectively. E.coli (33.3%) and Streptococcus (21.43) were the most isolated microorganisms from uterine bacterial culture. We could conclude that the ultrasonography is a rapid, reliable diagnostic technique for mare endometritis, when combined with endometrial cytology and bacteria isolation.
[Show abstract][Hide abstract]ABSTRACT: The present study aimed at instigating the buffalo ovarian and uterine response to ovsynch protocol when initiated 21 days postpartum (pp). Animals were arranged into a treated (n = 3) and a control (n = 3) group. The treated group was given the first dose of GnRH on day 0 (day 21 pp) followed by PGF2 alpha on day 7 and the second dose of GnRH on day 9. All animals were allowed a daily ultrasound examination from day 1 to day 9 and then every 12 h until detection of ovulation. The ovarian response of the treated group clearly showed the organized events of follicular growth ended by ovulation in one animal (33.3%) of the treated group; the changes in the small, medium, large and total follicle population and area did not differ significantly between the two groups; luteinization of the dominant follicle following the first GnRH injection in two animals (66.6%) indicated the reliability of the ovsynch strategy to improve the ovarian function; the uterine response was clearly evidenced by increasing the uterine wall homogeneity, decreasing the uterine lumen (less than 0.3 cm) and clearing contents by day 7 - 8 in the treated group. In conclusion, the ovsynch protocol has a beneficial effect on the ovarian function and uterine involution when applied 21 days pp in buffaloes.
[Show abstract][Hide abstract]ABSTRACT: The intensity of heat signs in buffaloes is generally low and the incidence of suboestrus varied from 15 to 73% (Buffalopedia). The objective of this study was to investigate the feasibility of monitoring the changes in some milk constituents, oestradiol levels and electrical conductivity of vaginal mucus during peri-oestrous period in prediction of the timing of oestrus in buffaloes. Twenty-one Egyptian buffaloes aged 3-9 year, 1st-6th lactations, were examined by oestrous detector and ultrasonographically for monitoring the ovarian and uterine activity for 7 days around the time of standing oestrus. Sodium, potassium, chloride and lactose were assayed in aqueous phase of milk; besides, oestradiol was estimated in serum. Current results declared highly significant acute changes in milk constituents at the time of oestrus characterized by peaking of chloride and sodium levels and lowering of potassium and lactose values. The alternation in milk composition when arranged in decreasing order of magnitude, sodium was the highest (77.78 ± 0.69%), followed by chloride (61.60 ± 1.52%) and potassium (-58.14 ± 10.89%). Concomitantly, milk lactose decreased by 26.07 ± 7.97% compared to baseline levels. Synchronously, vaginal electrical resistance (VER) showed a significant (p < 0.01) decrease, but serum oestradiol 17β levels surged (59.93 ± 7.29 pg/ml) on day of oestrus. Serum oestradiol level was negatively correlated with VER (r = -0.577), potassium (r = -0.661), positively correlated with chloride (r = 0.707) and sodium (r = 0.579) and not correlated with lactose levels. These results for the first time suggested that the changes in constituents of milk during peri-oestrous period may be used as a practical non-invasive indicator for oestrous detection and prediction of ovulation in Egyptian buffaloes.
[Show abstract][Hide abstract]ABSTRACT: The current study was designed to find out the effect of different doses (8, 12 or 16
µg) of GnRH analogue (Buserelin acetate, BA) on the ultrasonographic picture and biometry
of buffalo bulls' reproductive organs. Animals (n= 9, aged 15-18 months) were allocated into
three groups (n= 3/group) according to the hormonal dose that was administered once
weekly for six weeks. Results revealed that the testicular diameter and epididymal tail width
did not differ significantly before and after treatment.
[Show abstract][Hide abstract]ABSTRACT: To clarify the effect of lactation period on ovarian follicular activity and associated hormonal levels in goats, six goats were monitored daily by ultrasonographic examination with blood sampling during early (Days 5 to 25; Day 0 was the day of kidding) and late (Days 40 to 60) lactation. While the presence of a corpus luteum of pregnancy retarded follicular growth in the ipsilateral ovary until Days 11-13 postpartum, the total follicular number (TFN) and area (TFA) increased during late lactation due to the significant increase in the number of medium- and large-sized follicles and decrease in the number of small follicles. Four goats showed a similar pattern of follicular development during the period studied characterized by the emergence of five and six waves during the early and late lactation, respectively. The largest follicle diameter of the first three waves monitored during early lactation was significantly smaller as compared with the diameter of those existing during late lactation. TFN showed a positive correlation with FSH but showed a negative correlation with immunoreactive (ir-) inhibin and estradiol during the postpartum period. TFA was positively correlated with ir-inhibin, estradiol and PRL and negatively correlated with FSH during the monitored periods. The plasma levels of ir-inhibin and progesterone were significantly higher during late lactation compared with the levels recorded during early lactation. Ir-inhibin levels showed a significant positive correlation with LH and estradiol during early and late lactation but showed a negative correlation with FSH during the whole lactation period. LH was positively correlated with estradiol and PRL during early and late lactation, respectively. These results suggest that the lactation period has a detrimental effect on ovarian activity during the early postpartum period in goats.
Article · Oct 2011 · Journal of Reproduction and Development
[Show abstract][Hide abstract]ABSTRACT: Melatonin is a multifunctional molecule that mediates several circadian and seasonal reproductive processes. The exact role of melatonin in modulating reproduction, however, is not fully understood-especially its effects on the ovarian follicles and oocytes. This study was conducted to investigate the expressions of the ASMT and melatonin-receptor MTNR1A and MTNR1B genes in bovine oocytes and their cumulus cells, as well as the effects of melatonin on oocyte nuclear and cytoplasmic maturation in vitro. Cumulus-oocyte complexes (COCs) from abattoir ovaries were cultured in TCM-199 supplemented with melatonin at concentrations of 0, 10, 50, and 100 ng/ml. The expression of ASMT, MTNR1A, and MTNR1B genes was evaluated by RT-PCR. Moreover, the effects of melatonin on cumulus cell expansion, nuclear maturation, mitochondrial characteristics and COCs steroidogenesis were investigated. Furthermore, the level of reactive oxygen species (ROS) was evaluated in denuded oocytes. Our study revealed that ASMT and MTNR1A genes were expressed in COCs, while the MTNR1B gene was expressed only in oocytes. Additionally, melatonin supplementation at 10 and 50 ng/ml to in vitro maturation medium significantly enhanced oocyte nuclear maturation, cumulus cell expansion and altered the mitochondrial distribution patterns, but had no effects on oocyte mitochondrial activity and COCs steroidogenesis. Melatonin-treated oocytes had a significantly lower level of ROS than controls. The presence of melatonin receptors in COCs and its promoting effects on oocyte nuclear and cytoplasmic events, indicate the potentially important roles of this hormone in regulating bovine oocyte maturation. Moreover, the presence of ASMT transcript in COCs suggests the possible involvement of these cells in melatonin biosynthesis.
Article · Apr 2011 · Molecular Reproduction and Development
[Show abstract][Hide abstract]ABSTRACT: The present study was conducted to characterize follicular development and its hormonal control during early pregnancy in goats. The ovaries of goats (n=8) were scanned daily for follicles (> or = 2 mm in diameter) and corpora lutea by transrectal ultrasound with blood sampling from the jugular vein for monitoring the hormonal changes during the first thirty-five days after mating. During early pregnancy, three (37.5%), four (50%) and one (12.5%) goat showed nine, eight and seven waves of follicular development, respectively. The corpora lutea were detected as early as Day 3.61 ± 0.45 (7.47 ± 0.43 mm) of pregnancy (Day 0=day of mating) and attained their maximal cross-sectional diameter (10.64 ± 0.37 mm) on Day 25.7 ± 0.8 of pregnancy, respectively. A transient rise in FSH levels was temporally associated with the day of follicular wave emergence (up to three days prior to wave emergence). The plasma LH and estradiol levels were negatively correlated with the progesterone concentration. The rise in plasma immunoreactive (ir) inhibin levels was negatively correlated with the FSH concentration and positively correlated with the number of large-sized follicles. Alternatively, the mean plasma ir-inhibin levels showed a noticeable decline with the progression of pregnancy. The present results demonstrated that follicular development during early pregnancy shows a wave-like pattern, with seven to nine waves developing until Day 35 after breeding, and that the number of follicular waves can be predicted by the number of FSH peaks. The current study also demonstrated that the role of inhibin as an FSH regulator is maintained throughout early pregnancy.
Article · Oct 2010 · Journal of Reproduction and Development
[Show abstract][Hide abstract]ABSTRACT: The current study was performed to follow up the circulating hormonal changes and to correlate the findings with the physiological activity of the corpus luteum (CL) and placenta during pregnancy in goats. Blood samples were collected weekly from five goats during pregnancy for measuring steroid and protein hormones. A gradual increase was observed in immunoreactive (ir-) inhibin, with maximal levels at the 17th week. The plasma concentrations of estradiol and prolactin (PRL) showed nearly similar patterns during pregnancy, where they declined to basal levels during the first 4 weeks post-breeding and then increased significantly, with the maximal concentration during late pregnancy. The plasma FSH and LH concentrations were maintained at basal levels throughout the gestation period. The plasma progesterone concentration abruptly increased in the first week post-breeding and remained at high values throughout the pregnancy period. Immunohistochemical localization of inhibin alpha, beta(A), beta(B) and steroidogenic enzymes cytochrome P450 aromatase, 3alpha-hydroxysteroid dehydrogenase (3betaHSD), cytochrome 17alpha-hydroxylase P450 and cholesterol side-chain cleavage cytochrome P450 in the cyclic and pregnant goat CL revealed positive immunoreactivity without affinity differences between the luteal and pregnancy stages. The placental syncytiotrophoblasts also showed positive staining, except for inhibin beta(A) and 3betaHSD. The giant binucleate cells of the placenta showed positive immunoreactions to PRL. These results suggest that the high concentrations of ir-inhibin, estradiol and PRL during late pregnancy are of placental origin and that the placenta may have a vital role in the maintenance of pregnancy, regulation of mammary growth and preparation for kidding and lactation in goats.
Full-text available · Article · Apr 2010 · Journal of Reproduction and Development