This study was carried out to investigate the efficacy of PGF(2alpha) for oestrus synchronization (ES) in Awassi ewes to which were administered the progestagen-PMSG combination, and to evaluate the effect of the exogenous GnRH administration immediately after the artificial insemination (AI) on their pregnancy rate and lambing performance during the breeding season. The ewes (n = 33) were treated with an intravaginal sponge impregnated with 30 mg fluorogestane acetate for 12 days and were injected with 500 IU PMSG at the time of removal of the sponge. The ewes were then divided into three equal groups of 11 ewes each. One millilitre of physiological saline (0.9% NaCl; placebo) was administered to each ewe in Group 1 at the time of second AI. Approximately 4 microg GnRH (busereline) was injected to each ewe in Group 2 immediately after second AI. A total of 150 microg PGF(2alpha) (cloprostenole) was injected at the time of sponge removal on day 12 and 4 microg GnRH immediately after the second AI was also treated to each ewe in Group 3. Intracervical AI with diluted fresh semen was performed twice at 12 and 24 h following the onset of oestrus. The injection-oestrus onset and injection-oestrus-end interval in Group 3 was significantly (p < 0.001) shorter than both Groups 1 and 2. Although the pregnancy rates of Groups 2 and 3 (81.8%; 9/11) were numerically higher than of Group 1 (63.6%; 7/11), the difference among the groups was statistically insignificant. The multiple birth rate of Group 3 was found higher than Groups 1 and 2. However, the number of single lambs of Group 1 was also higher than Groups 2 and 3 (p < 0.05). Despite the litter sizes of Groups 2 (1.27; 14/11) and 3 (1.55; 17/11) being numerically higher than Group 1 (0.73; 8/11), the differences among all the groups were statistically insignificant. In conclusion, the administration of PGF(2alpha) at the time of removal of the sponge shortens the injection oestrus-onset and oestrus-end interval in Awassi ewes treated with progestagen-PMSG. Additionally, exogenous GnRH treatment immediately after the AI increases the multiple birth rate of Awassi ewes synchronized with progestagen-PMSG-PGF(2alpha) combination.

The objectives of this study were to investigate whether the use of intravaginal sponge for estrous synchronization of goats causes oxidative stress, and to examine the effect of administering vitamin E during preovulatory period on reproductive performance of estrous synchronized goats. Estrus was synchronized in 36 non-lactating adult does using intravaginal sponges containing 30 mg of fluorogestane acetate (FGA) for 14 days. All females received 500 IU of eCG at the sponge withdrawal. The goats were allocated at random to two groups balanced for breed, age and body weight. Treatment group (n=18) received 200mg of vitamin E i.m. at the time of sponge removal and again at the time of second artificial insemination. The other 18 goats (control) were administered 1 ml of physiological saline instead of vitamin E on each of these two occasions. All does in estrus was intracervically inseminated at 12 and 24h after the onset of estrus. Blood samples were collected every 72h during the experimental period for evaluation of malondialdehyde (MDA) and vitamin E concentrations. Serum MDA level increased and vitamin E concentration decreased during the period of vaginal sponge application. Following the sponge removal, MDA level declined rapidly to below basal level in the treatment group but remained high in the control group. Conversely, vitamin E concentration increased in the treatment group after the sponge withdrawal and remained at a low level in the control group. No statistically significant differences (P>0.05) were observed between groups in terms of estrous response, conception rate, gestation length or kidding rate. However, the number of multiple births (70.0% versus 50.0%) and prolificacy rate (2.40+/-0.37 versus 1.63+/-0.26 kids per kidding) were significantly higher (P<0.05) for the treatment group than those of the control group. The results indicate that the use of intravaginal sponges for estrous synchronization of goats causes an increase in level of oxidative stress. However, the vitamin E treatment during preovulatory period can prevent the overproduction of reactive oxygen species (ROS), and it may improve the multiple birth rates and the number of kids born in estrous synchronized goats.

The aim of this study was to determine the effects of dexamethasone on sperm characteristics and hyaluronidase activity of serum and semen. In this investigation, 14 healthy Akkaraman rams, at the age of 2 years and weighing between 50-60 kg, were used. The rams were randomly divided into two groups. After the last administration of dexamethasone intramuscularly at a dose of 0.25 mg/kg, semen and blood samples were taken at different times. The results showed that the serum hyaluronidase activity was increased significantly (p<0.001) in the treatment group when compared with the control group except for the 1st hour. There was a significant difference (p<0.001, 0.01, 0.05) in the hyaluronidase activity of semen between the treatment group and the control group. Furthermore, there was a significant difference (p<0.01) in sperm concentration between both groups at all the times except the 96th hour. There were statistically significant (p<0.05) differences in semen volume between the treatment and control groups. There were also significant differences (p<0.05) in sperm motility between the treatment and control groups except for the 72 and 96th hours. These findings indicate that dexamethasone increases hyaluronidase activity of serum and semen, but it decreases sperm concentration, semen volume and sperm motility in rams. Therefore the use of these drugs in breeding rams during breeding season is not suitable.

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ABSTRACT. The effects of lincomycin-spectinomycin and sulfamethoxazole-trimethoprim combinations on the hyaluronidase enzyme of serum and semen and on sperm characteristics in rams were determined. Thirthy-two Akkaraman rams were used. The rams were randomly divided into four groups. Group A and group B were determined as control groups of group C (lincomycin-spectinomycin) and D (sulfamethoxazole-trimethoprim), respectively. Combinations of lincomycin-spectinomycin and sulfamethoxazole-trimethoprim were administered at doses of 15 mg.kg -1 intramuscularly and 12 mg.kg -1 body weights orally, respectively. Blood and semen samples were collected at 4,12,24, 48, 72, 192 and 384 hr. Semen hyaluronidase activities of rams in group C increased significantly (p<0.001, <0.05) compared with the control group at 24 and 48 hr, respectively. Semen hyaluronidase activities in group D rams also increased significantly (p<0.001) in comparison with the control group at all times except 72 and 384 hr. Serum hyaluronidase activities increased significantly (p<0.01, <0.001) at 24 and 48 hr after treatment of lincomycin-spectinomycin. Additionally, significant (p<0.05, <0.001) increases were detected in the serum hyaluronidase activities of group D at 48 and 72 hr, respectively. No significant correlation was found between serum and semen hyaluronidase activities. Furthermore, significant increases (p<0.05) were observed in the percentages of motile sperm in the rams of group C and D compared with the control groups. The values of sperm concentration and total number of sperm in group C and D rams decreased significantly (p<0.001) in comparison with control groups. No significant correlations were found between the semen hyaluronidase activities and sperm characteristics. In conclusion, these findings show that the combinations of lincomycin-spectinomycin and sulfamethoxazole-trimethoprim do not have any harmful effects on hyaluronidase activities and sperm motility. However, the use of both antibiotic combinations in breeding rams during the ramming season is not advisable due to the decrease of sperm concentration.