牦牛妊娠期卵巢、卵泡及黄体的形态学观测

对87头妊娠母牦牛卵巢及其表面的卵泡、黄体的形态学观测发现,牦牛妊娠后孕侧卵巢大小、质量显著增加(P<0.05),而对侧卵巢则无明显变化(P>0.05).妊娠4个月以后,卵巢逐渐变扁长,以孕侧更为明显.牦牛在妊娠期,卵巢上仍然有规律地出现非排卵卵泡波,但卵泡数比未孕状态下少.在卵巢表面,主要以Ⅰ类卵泡(直径≤5 mm)为主,为3~6个.在孕侧随妊娠的进行Ⅰ类卵泡数呈递增趋势,妊娠1个月为(2.3±1.8)个,妊娠6个月达到(6.6±5.2)个,而空侧数量变化不明显(P>0.05),整个妊娠期其卵泡数保持在5~7个之间.Ⅱ类(5 mm<直径≤10 mm)和Ⅲ类(直径>10 mm)卵泡数很少,妊娠2个月平均数分别为(0.7±0.5)个和(0.3±0.1)个.牦牛妊娠黄体一半以上不突出于卵巢表面,且黄体直径在整个妊娠期基本不变.

Morphological observation of ovary and ovarian follicle of pregnant yak

Eighty-seven female yaks were used in the present study to investigate the morphological changes of their ovary,ovarian follicle and corpus luteum in different pregnant stages.The results showed that the size and weight of the ovaries in the side of gravid horn were increasing dramatically with the extending of gestation(P<0.05),while no obvious changes were observed about the size and weight of ovaries in the side of nogravid horn(P>0.05).After 4 month of gestation,both sides ovary became flatter and longer gradually,and this change was more evident in the homonymy gravid horn ovary than the antigravid horn's.Although some follicles were still present in pregnant yaks,the numbers of ovarian follicles were less than no pregnancy's dramatically.The diameter of most of ovarian follicles lay on the surface of ovary were less than 5 mm(groupⅠ)during pregnancy,and the mean number of groupⅠ ovarian follicles was 3 to 6.On the surface of the homonymy gravid horn ovary,the number of follicles of group Ⅰwas increasing with the development of pregnancy.The average numbers were 2.3±1.8 within the first month of gestation and were 6.6±5.2 within the 6th month of gestation.However,on the surface of the homonymy antigravid horn ovary,the number of groupⅠ of follicles had no obvious change,It was 6.7±4.4 during in the first month of pregnancy.Contrasted to groupⅠ,the follicles number of groupⅡ(5 mm10 mm) were smaller in both side ovaries(0.7±0.5 and 0.3±0.1,respectively) during the second month of pregnancy.The diameter of corpus luteum was almost invariability during pregnancy,and less than half of corpus luteum was protrudent to the surface of the ovary.