The present study was carried out to investigate the effect of different seasons on length and duration of estrus as well as to observe the behavioral changes and physiological peculiarities during estrus period. Three climatic seasons and age groups were considered: summer (March-June), rainy (July-October) and winter (November-February); A (6-9 month), B (9-12 month) and C (>12 month). Estrus behavior was monitored twice a day, using a teaser buck. The estrus were quantified within each season and classified as short (<17 days), normal (17-25 days) and long (>25 days). In case of seasonal effect, the length of estrous cycle did not differ significantly (P>0.05). The higher length of estrous cycle was found in summer (23.50±1.57 days) followed by winter (21.33±1.01 days) and rainy season (20.79±0.61 days), respectively. On the other hand, duration of estrus showed significant (P≤0.05) differences among the three different seasons. The longer duration was observed in winter (44.00±1.95 hours) followed by summer (36.00±0.70 hours) and rainy season (35.54±0.80 hours), respectively. Higher percentage of normal estrus was observed during rainy season (79.31%) when compared to winter (72.73%) and summer (53.33%). On the other hand, a greater percentage of short and long estrous cycle was reported in summer followed by winter and rainy season. Moreover, length of estrus and its duration did not differ significantly (P>0.05) with age. The mean of rectal and vaginal temperature during estrus were recorded as 39.30±0.05 °C and 39.60±0.03 °C, respectively. However, seasonal variation on post-partum heat period did not differ significantly (P>0.05). The mean post-partum heat period of Black Bengal does among the seasons was observed as 84.56±3.28 days. The present result on estrus behavior of Black Bengal goat could help to boost up effective artificial insemination of goat population for optimizing productivity under intensive condition.

Ginseng is known as the king of all herbs in terms of antioxidant and anti-inflammatory activities and recently has become more involved in the treatment of neurological diseases. In this regard, this study aimed to determine the effects of Ginsenosides on pentylenetetrazol-induced epilepsy during the estrus cycle. For this purpose, 30 rats were randomly divided into five groups, namely control (saline), valproic acid (VPA, 75 mg/kg), Ginsenosides (50 mg/kg), Ginsenosides (100 mg/kg), and Ginsenosides (150 mg/kg) with four subgroups (proestrus, estrus, metestrus, and diestrus). Subsequently, the initiation time of myoclonic seizures (ITMS), initiation time of tonic-clonic seizures (ITTS), and seizure duration (SD) were determined. According to the results, ITMS and ITTS significantly increased in the VPA-treated group (P<0.05). Ginsenosides (100 and 150 mg/kg) administration significantly increased ITMS and ITTS (P<0.05). Moreover, the ITMS and ITTS in Ginsenosides-treated rats were significantly higher in luteal phases, compared to the follicular phase (P<0.05). In addition, pretreatment with VPA significantly decreased SD, compared to the control group (P<0.05). A significant decrease in SD was observed in the rats pretreated with ginsenosides (100 and 150 mg/kg) (P<0.05). Seizure duration significantly decreased in animals that received Ginsenosides in luteal phases, compared to the follicular phase (P<0.05). These results suggested that Ginsenosides have anticonvulsant effects that are more prominent during the luteal phase than the follicular phase.

Due the fact that during estrus cycle the genital organs are affected by female reproductive hormones, the physiologic changes more likely will reflected in structural alterations of genital organs. For determination of histological changes during estrus cycle, 20 genital organs from 4-8 years old buffalos were collected from abattoir and 10 specimens were appointed to each phases of estrus cycle. The tissues were stained with H&E, PAS, Verhoeff, Toluidine blue and VanGeisson's methods, respectively for general histological study, carbohydrate, elastic fibers, mast cells, and collagen fibers. Mucosal epithelium was simple columnar and some cells were ciliated and some others recognized by extensive and clear cytoplasm. Epithelium in follicular phase contained PAS positive granules more than the leuteal phase. Collagen fibers revealed more in deep region of mucosa-sub mucosa and between bundles of muscles. Elastic fibers were observed in connective tissue of tunica muscular is and around of blood vessels. Mast cells were observed in mucosa-sub mucosa and tunica muscularis. We conclude that; the epithelium of uterine cervix in follicular phase of estrus cycles has secretary activity. The structural firmness and solidity of this organ most probably is due to presence of collagen fibers in mucosa- sub mucosa layers. More likely, the mast cells involving in histological changes of the cervix during estrus cycle.

Synchronization can improve the reproductive performance of ewe lambs during the non-breeding season, though seeking a simple method can be more practical for farmers. Accordingly, the study aimed to evaluate the reproductive performance of ewe lambs during the non-breeding season using different clomiphene citrate (CC) protocols compared with progesterone sponge (PS) + equine chorionic gonadotropin (eCG) protocol. In this study, 40 Ghezel ewe lambs were divided into four randomly groups: 1) PS + eCG group: PS insertion (day 0-12) + 500 IU eCG injection on day 12,2) PS + CC group: PS insertion (day 0-12) + oral administration of 100 mg CC/day (day 7-12),3) CC + eCG group: oral administration of 100 mg CC/day (day 7-12) + 500 IU eCG injection on day 12,4) CC group: oral administration of 100 mg CC/day (day 7-12). Ram introduction was done for five days. Blood samples were taken on 1, 11, 14, and 40 days, and serum levels of estradiol and progesterone were measured. Pregnancy and lambing rates were also assessed. Results indicated that pregnancy and lambing rates were the highest in PS + eCG group, while the lowest or no performance was observed in CC groups (P<0. 05). Based on the overall results of the present study, the best synchronization method during the non-breeding season for ewe lambs was PS + eCG compared with the CC protocols.

This study was conducted to evaluate the estradiol and progesterone profiles of 6 adult, cyclic Arabian mars during estrous cycle. Blood samples were daily collected via jugular venopuncture. Plasma was separated by centrifugation and stored at -20°C till measuring by radioimmunoassay (RIA) technique. The mean of plasma progesterone and estradiol concentrations were analyzed by analysis variance (repeated measures test using GLM; SPSS). Results showed that the mean (±SEM) of progesterone concentrations was below 1 ng/ml during estrus stage. The progesterone concentration increase to 2.87±0.64ng/ml within 24 hours after ovulation. The progesterone concentration increased significantly from day 1 to day 6 (P<0.05; 2.87±0.44 to 12.7±3.94 ng/ml) of estrous cycle. Between days 7 to 14 of cycle, progesterone concentration was over 1ng/ml, which start to decreased (P<0.05; 0.8±0.3ng/ml) during day 14 and 15 to get the basal level. The mean (±SEM) of estradiol concentration was 108.26±32.00 pg/ml 2 days before ovulation. During day 1to 22 it was 31.90±11.60 to 92.20±27.20 pg/ml, which increased (P<0.05) during day 23 to 24. The peak of estradiol concentration (106.9±37.8 pg/ml) occurred on day 24 of the estrus cycle. The mean length of estrus cycle and estrus period (P4<1 ng/ml) was 23 and 9.6 days, respectively.