| The concentration of reproductive hormones in the blood plasma, the number and the morphology of different vaginal cells had significant dynamic variation at different stages of the estrous cycle, while the change regularity of different species are different. Ganjia sheep is a typical seasonal estrus in mammals and live in tibetan plateau at an altitude of 2800-3500 meters,which produced only one lamb each year.The low fecundity of Tibetan sheep has seriously affected the rapid development of Tibetan sheep breeding industry. The mastery of the change regularity of reproductive hormones concentration,the number and the morphology of different vaginal cells is of great significance to the application of the control technique of Tibetan sheep breeding.In order to accurately determine the estrous cycle, research the relationship between dynamic changes of FSH and LH secretion in the estrous cycle and the ovulation and the fecundity of Tibetan Sheep,and analyse the changes of reproductive hormone between breeding season and non breeding season, a total of 24 non pregnant female Ganjia Tibetan Sheep were selected, which were 3-4 years old,normotrophic and healthy in breeding season(July to September). According to the different stages of the estrous cycle of tibetan sheep were averagely divided into 4groups.These groups were as follows: proestrus, estrus, mestrus and diestrus. In no breeding season(January to June), 6 female Ganjia Tibetan Sheep were selected. This study adopted the following research methods :(1) The vaginal smears of different periods were made and the giemsa staining and microscopic methods were used to study the number and morphology changes of vaginal smear cell.(2) The content of FSH and LH was determined by enzyme immunoassay(ELISA) in proestrus, estrus,metestrus and diestrus and the relationship between dynamic variation rule of the secretion and ovulation were analysed.(3) The content of FSH and LH in non breeding season was determined by enzyme immunoassay and the comparisons of reproductive hormones between breeding season and non breeding season were made.The results were demonstrated as follows:1.The characteristics of FSH and LH secretion during the estrous cycle were as follows: The secretion of FSH and LH was pulsatile throughout the estrous cycle.Simultaneously,the diestrus was wavelike. The secretion of FSH and LH showed four distinct peaks value in the estrous cycle respectively.The peak of FSH were formed in the 2h,72 h,10d and 13 d, and the peak value of FSH respectively were 3.832 m IU/ml、3.440 m IU/ml、3.740 m IU/ml、3.838 m IU/ml. The peak of LH emerged in 0h、69 h 、 9d and 12 d and the peak value of LH respectively were 5.938 m IU/ml 、5.661 m IU/ml、5.791 m IU/ml、5.778 m IU/ml.And each peak value were not significantly different.2. The trends of the content of FSH and LH were similar on plasma and the basic trends were that the content of FSH and LH in estrous increased, the content in metestrus and diestrus decreased, and the content in proestrus increased again. During the estrous cycle, the secretions of FSH are the highest in estrus, and significant higher than other phases. The concentration of LH was the highest in estrus, but the difference between the four periods were not significant.3. The secretion of FSH and LH had significant regularity at different stages of the estrous cycle. The secretion of LH was always significantly higher than that of FSH(P<0.01).The base concentration, secretion peak value and secretion valley value of FSH and LH in estrus were significantly higher than that of the metestrus; and the amplitude of LH of the estrus was significantly higher than that of the metestrus. The base concentration, secretion valley value of FSH and LH in proestrus was significantly higher than that of the diestrus, but the peak value of FSH,the peak value and amplitude of LH were lower than that of the diestrus(P<0.05).4.The secretion of LH was significantly higher than the secretion of FSH(P<0.05).The amplitude of LH and FSH was significantly lower than that in the breeding season.5. The vaginal cells were mainly composed of parabasal cells, intermediate cells,nuclear epithelial cells(NEC), cornified epithelial cells(CEC),leukocytes and cell frag-mentins. The proportion of CEC reached maxmum at estrus and was significantly hi-gher than that of at other stages of the cycle(P<0.05).The proportion of NEC at proe-strum was significantly higher than that of at other stages of the cycle(P<0.05).The proportion of leukocyte of diestrus and estrus were significantly higher than that of proestrus and estrus. |
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