Variations in Reproductive Hormones during Estrus Cycle in Local Beef Cattle from Jilin of China

[ Objective] To provide a theoretical basis for improving reproductive efficiency of domestic beef cattle in Jilin of China. [ Method] China Red Steppe cattle, Yanbian yellow cattle and Simmental cattle in Jilin Province were used for detection. The levels of progesterone （P4）, estradiol （ E2 ）, follicle-stimulating hormone （FSH） and luteinizing hormone （LH） in serum and urine during estrus cycle were determined. [ Result] The levels of P4 and E2 were significantly different between pregnant cattle and non-pregnant cattle on Day 21 post estrus （ P 〈 0.01 ）. The level of LH on estrus day was significantly different from that on the other days of estrus cycle （ P 〈 0.05）. [ Conclusion] It is feasible to detect P4 level for diagnosis of estrus and eady pregnancy in beef cattle.

Relationship between estrus cycles and behavioral durations of captive female alpine musk deer

Owing to poor breeding success in captive alpine musk deer, an understanding of the behavioral patterns of muskdeer in captivity is important. This study was conducted from June 2004 to January 2005 at the Xinglongshan MuskDeer Farm, which is located within Xinglongshan National Nature Reserve, Gansu Province, China. Focal samplingand continuous recording were used to observe the behaviors of 51 female alpine musk deer (Moschus sifanicus),42 of which had completed a single estrus cycle and nine of which had completed two or more estrus cycles. Allanimals were adults that had been born and raised in captivity. The durations of 12 behaviors, including environmentalsniffing, moving and feeding, were recorded during the non-breeding seasons and behavioral patterns werecompared. The behavioral patterns of females that had completed a single estrus cycle and females that hadcompleted multiple estrus cycles were compared to assess potential behavioral differences. The results showed thatfemales who had only one complete estrus cycle demonstrated more resting behavior, but less feeding and locomotorbehavior than females who had completed multiple estrus cycles. Furthermore, single estrus cycle femalesdemonstrated tail-rubbing during the breeding season. The results may yield useful information that can be used indeveloping better musk deer farming practices.

Combined effects of Gymnema sylvestre and Pergularia daemia on letrozole-induced polycystic ovarian syndrome in rats

Objective:To investigate the combined therapeutic potential of Gymnema(G.)sylvestre and Pergularia(P.)daemia on letrozole-induced polycystic ovarian syndrome(PCOS)in rats.Methods:Thirty six healthy female Wistar rats with regular estrus cycles were randomly divided into six groups each of 6.GroupⅠreceived 1 mL of 0.5%carboxyl methyl cellulose orally and served as the vehicle control group,while groupsⅡtoⅥwere treated with letrozole(1 mg/kg body weight p.o.)for 21 days to induce PCOS.After induction of PCOS,groupⅡserved as the PCOS control group,without treatment;groupⅢreceived metformin(20 mg/kg body weight p.o.)as the standard group,and groupsⅣtoⅥreceived G.sylvestre(100 mg/kg body weight p.o.),P.daemia(300 mg/kg body weight p.o.),and the combination of G.sylvestre and P.daemia,respectively,for 28 days.Vaginal smears were collected from all rats daily throughout the study to determine the phases of the estrus cycle.After completing the treatment schedule,oral glucose tolerance test,serum lipid profile and reproductive hormonal analysis were carried out.Subsequently,the rats were sacrificed to collect ovary and uterus for histopathological examination.Results:The PCOS control rats showed a significant irregularity in the estrus cycle,hyperglycemia,and the altered serum lipid profile such as the increased low and very low density lipoprotein,triglyceride,and decreased high density lipoproteins.In addition,the PCOS control rats showed a significant increase in serum luteinizing hormone,testosterone,and estrogen,and decrease in follicle stimulating hormone and progesterone.These changes were significantly revoked in all the treatment groups.The test drugs also significantly reduced the gained ovary weight(P<0.001),and histopathology of the ovary showed almost normal ovary.Among the treatment groups,the group of combination treatment of G.sylvestre and P.daemia showed superior ameliorative results in PCOS parameters.Conclusions:Combination of G.sylvestre and P.daemia presents potent synergistic activity against hyperandrogenism,hyperinsulinemia,anovulation and follicular cysts in letrozole-induced PCOS rats.

Effect of Different Reproductive Stages and Culture Times on Domestic Cat <i>in Vitro </i>Oocyte Maturation

The domestic cat has been used as a model to carry out comparative research in assisted reproduction, to be applied in wild cats. The efficiency in domestic cat IVM concerning the reproductive status and/or cultivation times has previously been investigated;however, the studies were carried out separately. The objective of this research was to evaluate the maturation of oocytes of domestic cats of different reproductive stages using two different in vitro culture times. The ovaries were obtained by Ooforo-Salpingo-Hysterectomy of cats that were of the following groups: 1) prepubertal, 2) follicular, 3) pregnant or 4) in anestrus. Maturation was carried out with TCM199 medium supplemented with BSA for 24 h and 48 h. On average, 29 ± 25, 20 ± 15, 17 ± 9 and 17 ± 13 oocytes/cat were recovered from the prepubertal follicular, pregnant, and anestrus stages, respectively, but did not show a significant difference (P > 0.05). Also, meiotic maturation did not show a significant difference between the different reproductive stages at 24 h and 48 h, respectively (P > 0.05). However, in the prepubertal and follicular stages, greater oocyte maturation numbers were observed at 48 h compared to 24 h (P < 0.05). In contrast, the aforementioned result was not observed in the pregnant and anestrus stages (P > 0.05), indicating that the in vitro culture duration is an important factor during in vitro maturation of domestic cat oocytes.

Antifertility Activity of Hydroalcoholic Extract of Ocimum Basilicum Linn. Leaves on Female Wistar Rats

Objective To determine the effect of hydroalcoholic extract of Ocimum basilicum Linn. leaves on ovulation, implantation and maintenance of pregnancy in adult female cyclic Wistar rats. Methods Ocimum basilicum leaves extract （364 mg/kg and 624 mg/kg） was screened for its antiovulatory, antiimplantation and abortifacient activities. Vaginal smear of each rat was monitored daily during the 15-day treatment of the first experiment. Estimation of cholesterol in ovarian tissue and its histology was carried out to confirm its antiovulatory activity. In the second and third experiments, animals received treatment from 1st to 7th and 8th to 16th day of pregnancy, respectively. The number of implantations and litter size were determined through laparotomy on l Oth and 20th day of pregnancy, respectively in two tests. The treated groups were compared with pain control. Results A significant increase in duration of estrus cycle and diestrus phase was observed （P〈O.O01）. A significant decrease in ovarian weight and notable increase in ovarian tissue cholesterol level was also observed （P〈O. 001）. Weight of uterus in treated group was found to be decreased. Histological report showed presence of large corpora lutea in ovarian parenchyma. Neither antiimplantation nor abortifacient effect was observed in rats treated with both the doses of extract. Conclusion Hydroalcoholic extract of Ocimum basilicum interferes normal ovulation by disrupting the estrus cycle and prolonging diestrus phase thus, has a potential of being developed into a female contraceptive.