How to breed mice correctly? - briefly
Maintain a stable environment with temperature 20‑26 °C, humidity 40‑70 %, and a 12‑hour light cycle; supply nesting material, a balanced diet, and uninterrupted access to fresh water. Pair unrelated, healthy adults, monitor for pregnancy, separate the dam before parturition, and wean pups at three weeks to avoid overcrowding.
How to breed mice correctly? - in detail
Effective mouse breeding requires careful planning, controlled environment, and systematic record keeping. Begin with selecting genetically healthy stock. Choose individuals with desired traits, free from visible signs of disease, and verify their pedigree to avoid inadvertent inbreeding. Maintain a breeding ratio of one male to two–three females to maximize litter production while reducing stress.
Housing must provide stable temperature (20–24 °C) and humidity (40–60 %). Use individually ventilated cages or well‑ventilated racks with bedding that absorbs moisture and can be changed without disturbing the animals. Provide nesting material, enrichment objects, and a balanced diet rich in protein and essential micronutrients. Ensure ad libitum access to clean water.
When pairing, introduce the male to the female’s cage during the dark phase, when mice are most active. Observe for successful mating signs—mounting behavior and presence of a copulatory plug—within 24 hours. If no evidence appears, separate and retry after 48 hours. Record the date of pairing and observed mating to calculate gestation accurately.
Gestation in mice lasts 19–21 days. Monitor pregnant females for weight gain and provide additional nesting material as parturition approaches. Keep the cage undisturbed during delivery; intervene only if complications arise, such as prolonged labor or failure of pups to nurse.
Newborn litters typically consist of 5–8 pups. Verify that each pup receives adequate milk by checking for a full stomach and regular weight gain of 2–3 g per day. Separate the dam from the litter after the first 24 hours only if health concerns dictate. Maintain a clean environment by replacing soiled bedding daily.
Weaning occurs at 21 days. Transfer each pup to an individual cage labeled with its identification number, sex, and birth date. Continue a diet formulated for growing rodents and monitor growth rates until adulthood.
Maintain a breeding log that includes: parent identification, pairing dates, mating confirmation, birth dates, litter size, sex ratio, weaning dates, and any health observations. Use this data to adjust breeding strategies, avoid excessive inbreeding coefficients, and improve overall colony health.
Regular health surveillance is essential. Implement a schedule for veterinary examinations, parasite screening, and serological testing for common murine pathogens. Quarantine new arrivals for at least two weeks before integrating them into the breeding colony.
Sanitation protocols should involve weekly cage cleaning, periodic deep cleaning of racks, and disinfection of equipment with agents effective against rodent pathogens. Ensure that all staff follow strict biosecurity measures, including wearing gloves and lab coats when handling animals.
By adhering to these practices—selecting robust stock, providing optimal housing, monitoring reproductive cycles, ensuring proper neonatal care, and maintaining rigorous records and health checks—mouse breeding can be conducted reliably and ethically, yielding consistent, high‑quality offspring for research or other purposes.