Copulation and/or cohabitation with a pregnant female facilitate paternal behavior in male mice. However, their contribution to the rearing of the offspring is still not well understood. Our aims were to investigate the behavior of sires toward own or alien pups; the immediate consequences of the presence of fathers on the offspring and the behavior of the mother; and whether the exposure of juvenile males to newborn siblings, in an overlapping litters context, facilitates paternal behavior in C57BL/6 mice. We found that sires behaved paternally toward alien pups at both postpartum days 3 and 7; did not affect the behavior of the mother (e.g., licking and grooming, retrieval behavior, time in the nest, and crouching postures); and reduced the time offspring stayed alone in the nest. The exposure to newborn siblings did not promote paternal behavior in juvenile males. Therefore, sires are more paternal than usually described in the literature for laboratory mice, suggesting a facultative role in the rearing of the offspring. However, juvenile male mice, in contrast to juvenile females, could be adapted to leave the nest earlier without major contribution to the offspring.

中文翻译：

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父本和幼年雄性小鼠（C57BL / 6）对后代的饲养有贡献吗？

与怀孕雌性的交配和/或同居有助于雄性小鼠的父亲行为。然而，它们对后代饲养的贡献尚不十分清楚。我们的目的是调查公犬对自己或外来幼犬的行为；父亲在场对后代的直接后果以及母亲的行为；以及在重叠的垫料环境中将未成年男性暴露于新生儿兄弟姐妹中是否有助于C57BL / 6小鼠的父亲行为。我们发现，在产后的第3天和第7天，公牛的父亲表现出对小外星幼崽的表现。没有影响母亲的行为（例如，舔和修饰，恢复行为，在巢中的时间以及蹲下的姿势）；并减少了后代独自呆在巢中的时间。新生儿兄弟姐妹的接触并没有促进未成年男性的父亲行为。因此，与实验小鼠的文献相比，父系比通常的父系更具父系性，这表明在后代的饲养中具有辅助作用。但是，与雌性雌性相比，雄性雄性小鼠可以适应更早地离开巢，而对后代没有重大贡献。