How does a mouse wean its offspring? - briefly
A mouse ceases lactation at about three weeks of age, prompting the young to begin consuming solid food such as seed and grain pellets while the mother gradually reduces nursing visits. This transition is completed within a few days as the pups become fully independent feeders.
How does a mouse wean its offspring? - in detail
Mice begin weaning shortly after birth, typically around day 15 to 21 of the pup’s life. During the first two weeks, the dam supplies all nutrients through milk, which is rich in protein, fat, and antibodies. By the third week, the mother gradually reduces nursing frequency, encouraging the young to explore solid food.
The transition involves several coordinated changes:
- Milk production decline: Hormonal shifts, particularly decreased prolactin, lower milk synthesis. The dam’s mammary glands shrink, and pups receive fewer nursing bouts.
- Solid food introduction: The dam’s nest contains soft, grain‑based chow and occasional insects. Pups start nibbling on this material while still attached to the nipple, gaining exposure to new textures and nutrients.
- Digestive adaptation: Enzyme expression in the pup’s gut shifts from lactase‑dominant to amylase and protease activity, enabling efficient breakdown of carbohydrates and proteins from solid feed.
- Thermoregulation and independence: As nursing wanes, pups develop better thermoregulatory capacity, reducing reliance on maternal warmth. They begin to leave the nest briefly, practicing foraging behavior.
- Maternal behavior modification: The dam spends less time in the nest, increasing grooming of pups and defending the territory. She also begins to exhibit increased aggression toward adult intruders, limiting access to the nest.
By day 21, most pups consume sufficient solid food to sustain growth, and the mother ceases nursing altogether. The offspring are then fully capable of independent feeding, thermoregulation, and social interaction within the litter.