title: Effect of size and sex ration of litter on the sexual maturation of female mice.
abstract: The relationships between the size and sex composition of the litter and puberty in female mice were investigated. Both factors significantly affected the age of first vaginal oestrus; litter size accounted for 22% of the total variation in age at puberty, and litter sex composition for 8%. When no males or only one male was present in litters of 10 young the females matured significantly earlier than when two or more males were present.
mesh_terms: D000818:Animals; D001835:Body Weight; D004971:Estrus; D005260:Female; D051379:Mice; D011247:Pregnancy; D012744:Sex Ratio; D012741:Sexual Maturation; D013997:Time Factors; D014621:Vagina / Q000502:physiology