Salim B, Entwistle K W
J Reprod Fertil. 1982 Nov;66(2):729-34. doi: 10.1530/jrf.0.0660729.
The hybrids were carrying 50% (N = 4) or 75% (N = 4) zebu (Brahman) blood. The spermatogenic cells were labelled in vivo with [3H]thymidine. The relative frequencies of the seminiferous epithelial cycle stages, determined from examination of 6350 tubule cross-sections, did not differ between the 2 hybrid types examined, between regions of the testis or between testes within animals. Frequencies were generally similar to those for Bos taurus bulls except that the frequency of stage 4 tubules was lower and that of stage 8 tubules higher. The mean duration of the seminiferous epithelial cycle was 13.41 days and was similar for both types of hybrid. The durations of meiosis and spermiogenesis were calculated to be 20.7 and 17.4 days respectively, estimates which are similar to those for Bos taurus bulls. From the relative frequency of cell stages and estimates of the duration of the cycle, a time divisor of 5-11 days is suggested as being appropriate to determine daily sperm production from counts of spermatid reserves in testicular homogenates of these hybrid bulls.
这些杂种携带50%（N = 4）或75%（N = 4）的瘤牛（婆罗门牛）血液。生精细胞在体内用[3H]胸腺嘧啶核苷进行标记。通过对6350个曲细精管横断面的检查确定的曲细精管上皮周期各阶段的相对频率，在所检查的两种杂种类型之间、睾丸不同区域之间或动物体内不同睾丸之间并无差异。频率一般与普通牛公牛相似，只是第4阶段曲细精管的频率较低，而第8阶段曲细精管的频率较高。曲细精管上皮周期的平均持续时间为13.41天，两种杂种类型相似。减数分裂和精子发生的持续时间经计算分别为20.7天和17.4天，这些估计值与普通牛公牛的相似。根据细胞阶段的相对频率和周期持续时间的估计，建议以5 - 11天的时间除数来根据这些杂种公牛睾丸匀浆中精子储备的计数确定每日精子产量。
