Evans A M
Biol Reprod. 1986 Mar;34(2):322-6. doi: 10.1095/biolreprod34.2.322.
The rate of sexual maturation among female Sprague-Dawley rats was measured in a variety of intraspecific social environments. It was found that females of this strain differ from at least one other strain of laboratory rat in that neither age at vaginal perforation nor age at first estrus was affected in Sprague-Dawley females by the presence or absence of male, regardless of his age or breeding history. Sizes of first litter among females who mated at their first estrus were compared with those among females who were first inseminated at older ages. On average, females bred at first estrus produced litters that contained more than 3 fewer pups than females mated at older ages. This observation suggests that female Sprague-Dawley rats do not attain full reproductive competence until sometime after the onset of puberty.
在各种种内社会环境中测量了雌性斯普拉格-道利大鼠的性成熟率。结果发现，该品系的雌性大鼠与至少一种其他品系的实验大鼠不同，即对于斯普拉格-道利雌性大鼠而言，无论雄性大鼠的年龄或繁殖史如何，其是否存在均不会影响阴道开口的年龄或首次发情的年龄。将首次发情时交配的雌性大鼠的第一窝产仔数与较晚年龄首次授精的雌性大鼠的第一窝产仔数进行了比较。平均而言，首次发情时繁殖的雌性大鼠所产的窝仔数比年龄较大时交配的雌性大鼠少3只以上。这一观察结果表明，雌性斯普拉格-道利大鼠直到青春期开始后的某个时候才获得完全的生殖能力。
