摘要
Abstract (Summary)To identify factors important to the efficiency of artificial insemination in cattle, four studies were conducted. In the first study, the addition of cream to the inseminate was used in an attempt to increase accessory sperm number. On d 6 after insemination, 60 embryos were evaluated. The addition of cream to the inseminate had no effect on accessory sperm number. In the second study, cryopreserved semen of a marked bull (spermatozoa exhibiting a semi-flattened anterior head) was matched with semen from an unmarked bull (conventional sperm head shape) to determine competitively the effect of a deep uterine insemination on accessory sperm number. Forty embryos were recovered 6 d after insemination and the ratio of accessory sperm observed was different: 62:38 for unmarked semen in the uterine body and marked semen in the uterine horn, and 72:28 for unmarked semen in the uterine horn and marked semen in the uterine body ( P < .05). In the third study, superovulated cows were utilized to determine the effect of artificial insemination time on fertilization status and accessory sperm number. Cows were inseminated once at 0 h (n = 10), 12 h (n = 10), or 24 h (n = 10) after the first standing event. On d 6 after insemination, 529 embryos(ova) were recovered. Fertilization rates were 29% (0 h); 60% (12 h); and 81% (24 h)( P < .01). Percentages of embryos with accessory sperm were: 5 (0 h); 8 (12 h); and 41 (24 h) ( P < .01). In the fourth study, three experiments utilizing superovulated cows were conducted to provide a basis for distinguishing unfertilized ova from very early embryonic death. In Exp. 1, recovered d 6 unfertilized ova were classified morphologically as either: (1) typical, (2) satellite, or (3) fragmented. In Exp. 2, recovered d 6 unfertilized ova from the third study were classified morphologically, and typical ova were fixed. In Exp. 3, ultrastructural features of preovulatory, tubal-stage, and typical d 6 unfertilized ova were investigated. Preovulatory ova revealed normal ultrastructure; tubal-stage ova exhibited evidence of degeneration; typical d 6 ova were degenerated and contained no discernable organelles. The first three studies support the use of accessory sperm evaluation as an alternative measure of fertility. The final study provides a basis from which future embryologists may distinguish fertilization failure from very early embryonic death.
摘要译文
摘要（摘要）确定因素，重要的是人工授精在牛的效率，四项研究进行的。在第一项研究中，除了奶油的授精被用于试图增加附件精子数。对于d 6授精后，60胚胎进行了评价。添加奶油的授精对附件精子数没有影响。在第二项研究中，一个明显的牛市冷冻精液（精子表现出半前扁平头）与精液从匹配一个没有标志的公牛（传统的精子头部的形状），以确定对竞争力的精子的配件数量深宫内人工授精的效果。四十胚胎恢复6天受精后的精子配件的比例观察不同：62:38在子宫体无人盯防的精液和精子标注在子宫角和72:28在子宫角无人盯防的精液和精液标在子宫体（P所述.05）。在第三项研究中，超排卵的奶牛用来确定的人工授精时间施肥现状及配件精子数量的影响。母牛在0小时（10例），12小时（10），或所述第一站在事件后24小时（10）授精一次。在D 6受精后，胚胎529（OVA）进行回收。受精率分别为29％，25（0 H）;60％25（12小时）;和81％25（24小时）（P＆所述; 0.01）。胚胎辅助精子百分比分别为：5（0 H）;8（12小时）;和41（24小时）（P＆所述; 0.01）。在第四个研究中，利用超排卵奶牛3实验以从非常早期胚胎死亡区分未受精的卵子提供基础。在进出口。1，回收ð6未受精的卵子被形态分类为：（1）＆NBSP;典型，（2）及NBSP;卫星，或（3）＆NBSP;分散。在进出口。2，从第三项研究中回收ð6未受精的卵进行分类的形态，和典型卵子是固定的。在进出口。3，超微结构排卵前，输卵管阶段，和典型ð6未受精的卵的特性进行了调查。排卵前的卵子显示正常超微结构;输卵管阶段OVA变性展出证据;典型ð6卵子是退化和不含可辨别的细胞器。前三个研究支持使用附件精子评价作为生育的替代措施。最后的研究提供了依据从未来的胚胎学家可以区分受精失败从非常早期胚胎死亡。
Dalton, Joseph Charles. Factors important to the efficiency of artificial insemination in single-ovulating and superovulated cattle[D]. US: Virginia Polytechnic Institute and State University, 1999