In rat models, large litter groups during suckling are used in the study of undernutrition. Large litter sizes are known to promote alterations in memory processes and anxiety-like behavior. Nevertheless, the effect of large litter size on sexual behavior and the reproductive system is still unknown. Environmental enrichment has been reported to (EE) enhance behavior and to correct some of the alterations produced by postnatal undernutrition. We used the Elevated Plus Maze (EPN), Morris Water Maze (MWM), Object Recognition test (OR) and several parameters of sexual behavior to determine the effect of large litter size on rats exposed to enriched and non-enriched environments. Newborn Wistar rats of both sexes were assigned to be suckled under lactation conditions, in litters of 8 pups or 16 pups. The large litter size (16 pups) caused a reduction in weight gain during the lactation period. On PND 45, four experimental groups were established for both sexes: Well-nourished Non-enriched (WN); Well-nourished Enriched (WE); undernourished Non-enriched (UN); Undernourished Enriched (UE). On PND 90, the UN males spent more time in the open arms on EPM. On PND 100, the UE females increased the latency to find the platform in training days (D1-4) in MWM. On probe day (D5) the UE males spent more time in the target quadrants in MWM. On PND 110, irrespective of EE the large litter size had increased the exploration time in both groups (UN) and (UE) in OR test. On PND 120, the performance of sexual behavior was more evident by effect of EE irrespective of the litter size. In conclusion, the large litter size showed no effects on sexual behavior, in contrast, EE has a sharp influence on sexual behavior. Conversely, memory processes and anxiety-like behavior are altered by large litter size.

在大鼠模型中，哺乳期间的大窝用于营养不良研究。众所周知，大窝会促进记忆过程和焦虑样行为的改变。然而，大窝产仔数对性行为和生殖系统的影响仍然未知。据报道，环境丰富可以 (EE) 增强行为并纠正出生后营养不良造成的一些改变。我们使用 Elevated Plus Maze (EPN)、Morris Water Maze (MWM)、物体识别测试 (OR) 和性行为的几个参数来确定大窝数量对暴露于丰富和非丰富环境的大鼠的影响。两性的新生 Wistar 大鼠被分配在哺乳条件下以 8 只幼崽或 16 只幼崽为一窝进行哺乳。较大的窝产仔数（16 只幼仔）导致哺乳期体重增加减少。在 PND 45 上，为两性建立了四个实验组： 营养良好的非浓缩 (WN)；营养丰富（WE）；营养不足非强化（UN）；营养不良者（UE）。在 PND 90 上，联合国男性在 EPM 上花费了更多的时间。在 PND 100 上，UE 女性在 MWM 的训练日 (D1-4) 中增加了找到平台的延迟。在探测日 (D5)，UE 男性在 MWM 的目标象限中花费了更多时间。在 PND 110 上，无论 EE 大小如何，在 OR 测试中，大窝产仔数都增加了两组 (UN) 和 (UE) 的探索时间。在 PND 120 上，无论窝产仔数如何，EE 的影响都更明显地表现出性行为。总之，大窝产仔数对性行为没有影响，相比之下，EE对性行为有很大的影响。相反，较大的窝产仔数会改变记忆过程和类似焦虑的行为。