Abstract: Objective\ To observe and analyze the reproductive capacity and the breeding regularity of different foetal numbers in BALB/c nude mice.Methods\ 160 seed mic e (80 male mice and 80 female mice)were observed and statistically classified acco rding to the data of the breeding cards.Results\ The pregnant rates of BALB/c nude mice was 95%.The average foetal number of each female nude mouse was 3.09±1.23 and the average breeding number was 7.21± 2.74. The number of all homozygotes was 50.23 percent of all breeding number and the average homozygote number of each nest was 3 64±1 57.The wean number of homozygotes was 88.32 pe rc ent of homozygote number and the average wean number of each nest was 3.22±1.83 .The reproductive capacity was the best at the second and the third foetal numbe r,took second place at the first and the fourth foetal number and was the worst at the fifth foetal number.Conclusion\ The breeding of BALB/c nude m ice is fine in the third grade barrier system,but seed mice should be changed af ter the third or the fourth foetal number is bred.

Key words: Naked little mouse/BALB/cs department, Breed performance, System of protective scr een

摘要： 目的　观察分析BALB c系裸小鼠不同胎次的繁殖能力和繁殖规律。方法　以 160只种鼠雌雄各半为研究对象 ,根据其繁殖卡的详细资料 ,进行分类统计。结果　BALB c裸小鼠怀孕率 95% ,平均每只母鼠怀孕 (3 0 9± 1 2 3 )胎 ,平均产仔数为 (7 2 1± 2 74)只 ;纯合子数占总产仔数的 50 53 % ,平均窝纯合子数 (3 64± 1 57)只 ;纯合子离乳数占纯合子数的 88 3 2 % ,平均窝纯合子离乳数 (3 2 2± 1 83 )只。其繁殖性能以第 2、3胎最好 ,第 1、4胎次之 ,第 5胎最差。结论　BALB c系裸小鼠在三级屏障系统内生长繁殖良好 ,每只雌鼠最好繁殖 3胎或 4胎即要更换种鼠

关键词: 裸小鼠BALBc系, 繁殖性能, 屏障系统