不同输精次数对回收受精卵的影响

按胚胎移植操作规程,发情后每隔12h输精1次,连输3次,结果回收卵中出现受精卵仅占38．2％。为了解决这个问题,我们改为每隔6h输精1次,直到发情结束。结果在回收卵中授精卵达到96．7％,说明了缩短输精间隔,增加输精次数能有效增加受精卵数量。     

Notes on the occurrence of tubercular spines in Schistosoma margrebowiei and Schistosoma mattheei

Scanning electron microscopical (SEM) studies on the tegument of the bovid schistosomes, Schistosoma margrebowiei and Schistosoma mattheei have yielded conflicting results; certain authors observed the tubercles on the tegument of these species to be spined, while others reported that they are spineless. The present study indicates that the protrusion of tubercular spines is subject to phenotypic plasticity regulated by external factors such as the identity of the host species and whether or not the schistosome is paired.     

Egg polymorphism of Schistosoma bovis

A study of the egg morphology of Schistosoma bovis from Sudan and Spain revealed some differences in the size and shape of eggs depending on the method of their sampling. The size of eggs (especially the length) tended to increase in the following order: those recovered from the worm uterus smaller than those recovered from the liver and from the faeces of mice for both strains. The shape of eggs from the host faeces (the typical ones) and from the distal portion of the worm uterus for both strains tended to be homogeneous whereas those from the host liver were more heterogeneous. A comparison between the eggs of the two strains showed a great similarity in spite of their distant geographical origins; only the length of the eggs collected from the distal part of the worm uterus and those from the host faeces showed a significant difference at a 99% confidence limit.     

黄牛利用活体采卵的应用研究

应用活体采卵仪对两组黄牛进行活体采卵.对黄牛每周2次和每周1次进行活体采卵,平均获卵分别为5.30枚、4.75枚,两者比较差异不显著(P>0.05);回收率分别为64.92%和81.85%,每周1次采卵回收率显著高于每周2次(P<0.05);优质卵母细胞率分别为80.12%和65.79%(P<0.01).健康和非健康牛只采卵,平均获卵母细胞数分别为6.71枚、5.10枚(P<0.05);回收率分别为65.28%、62.20%,无明显差异(P>0.05);优质卵母细胞率分别为79.91%、73.37%,差异不显著(P>0.05).     

聚乙烯吡咯酮与促卵泡素对奶牛活体采卵效率的影响

采用4×4拉丁方设计,研究聚乙烯吡咯酮(PVP)溶解促卵泡素(FSH)一次肌肉注射对奶牛活体采卵效率和体内血清FSH含量的影响。将8头荷斯坦空怀母奶牛随机分为4组,每组2头,分别用5mgFSH 5mL15%PVP(15%PVP组)、5mgFSH 5mL30%PVP(30%PVP组)、5mgFSH 5mL生理盐水(对照组)和常规注射FSH(常规组)处理供体奶牛。试验期4个月,每月处理1次,各组均为处理后4d应用B型超声波导引采卵。结果如下:30%PVP组每头次平均可采卵泡9个,获可用卵母细胞4枚,与常规组比较差异不显著(P>0.05),但与对照组比较差异显著(P<0.05);15%PVP组每头次平均可采卵泡6个,获可用卵母细胞2.25枚,与对照组比较差异显著(P<0.05);体内血清FSH浓度,30%PVP组与常规组变化趋势相似,维持适宜FSH浓度时间较长,15%PVP组次之,而对照组注射后4~12h血清FSH浓度较高,以后急剧下降,表明PVP可延长FSH在体内存留时间,但以30%PVP效果最佳。