摘要
The experiment was carried out in Southern Italy (41°N latitude) to examine the effects of seasonal variations of semen freezability in Leccese ram. Semen from five rams, collected every 2 weeks for a whole year, was frozen in straws, using a system based on Tris–fructose egg yolk as extender to constitute semen doses of 100×106 spermatozoa. Post-thaw survival and acrosomal status of cells were assessed by dual staining by Hoechst 33258 and FITC-PSA. Three different forms of fluorescence distribution were displayed indicating sperm without acrosome (unstained cells), sperm with damaged acrosome (cells with incomplete fluorescence over the head), sperm with widespread fluorescence (cells completely fluorescent). Motility and kinetic rating at thawing and after 1 and 3 h incubation (37 °C) were also assessed.
Semen frozen in summer and autumn, corresponding to the breeding season, showed the highest (PPPr=0.32) and after thawing (r=0.51).
In conclusion, the results show that season exerts a significant influence on semen freezability in Leccese ram, with the best performance occurring the summer and autumn period, corresponding to the reproductive season in temperate zones.
摘要译文
该实验在意大利南部（北纬41°）进行，以检查莱切公羊精液冻结季节变化的影响。来自五只公羊的精液，每2周收集一整年，采用以Tris-果糖蛋黄为扩充剂的系统冷冻成秸秆，构成精液剂量为100×10 6精子。通过Hoechst 33258和FITC-PSA的双重染色评估细胞的解冻后存活和顶体状态。显示了三种不同形式的荧光分布，指示没有顶体的精子（未染色的细胞），具有受损的顶体的精子（在头部具有不完全荧光的细胞），精子与广泛的荧光（细胞完全荧光）。还评估了解冻和1小时和3小时孵育（37℃）后的动力学和动力学评分。精液在夏季和秋季冻结，对应繁殖季节，最高（PPPr \x3d 0.32）和解冻后（r \x3d 0.51）。结论是，结果表明，季节对莱ra精子的精子冻结力有显着影响，夏秋季最好，对应于温带生殖季节。
A.G.D’Alessandro;G.Martemucci;. Evaluation of seasonal variations of semen freezability in Leccese ram[J]. Animal Reproduction Science, 2003,79(1-2): 93-102