How many pups does a Dumbo rat give birth to? - briefly
A «Dumbo rat» normally gives birth to six to eight pups per litter.
How many pups does a Dumbo rat give birth to? - in detail
The Dumbo rat, a laboratory strain distinguished by enlarged ears, typically produces litters ranging from three to eight pups. Average litter size centers around five individuals, although variations occur according to genetics, age, and husbandry conditions.
Key factors influencing offspring count include:
- Genetic background – selective breeding lines may shift the mean litter size upward or downward by one or two pups.
- Maternal age – females in their second and third estrous cycles often achieve the highest reproductive output; very young or senior rats show reduced numbers.
- Nutrition and health – diets providing adequate protein and energy, coupled with low stress environments, correlate with larger litters.
- Housing density – overcrowding can suppress fertility, leading to smaller broods.
Gestation lasts approximately 21–23 days, after which the dam delivers the full complement of pups simultaneously. Neonates weigh 5–7 g at birth and are altricial, requiring maternal care for the first three weeks. Mortality rates in well‑managed colonies remain below 5 %, meaning most litters reach weaning.
Comparative data:
- Standard Sprague‑Dawley rats: 6–12 pups per litter.
- Wistar rats: 5–10 pups per litter.
- Dumbo rats: 3–8 pups per litter, reflecting their distinct genetic line.
Breeding protocols recommend pairing a proven dam with a single male for 48 hours, then separating to prevent over‑mating. Monitoring estrous cycles and providing nesting material further optimize litter size and pup viability.