Observation on the changes of vaginal cells at different stages of estrous cycle in Duolang sheep

To ascertain the changes of vaginal cells at different stages of estrous cycle in Duolang sheep,vaginal smear method was used in five Duolang sheep with a normal estrous cycle,and the vaginal smear samples were collected and continuously observed by microscopic examination for 20 days.The results showed that the vaginal cells were mainly composed of keratinocytes,nucleated epithelial cells,and leukocytes.Keratinocytes constituted the majority in estrus,and there were no significant differences(P0.05) among three kinds of cells with similar number in metestrus;most of the cells were leukocytes in diestrus;most of the cells were nucleated epithelium cells in proestrus.According to the changes in cell types,the estrous cycle was determined,it was found that the duration of the different stages was as follows: metestrus(4±1)d,diestrus(9±3)d,proestrus(16±3)d,and estrus(2±1)d.It is indicated that the vaginal smear method can accurately determine the different stages of estrous cycle in Duolang sheep.