How do white rats reproduce? - briefly
White rats reproduce sexually; females become sexually mature at roughly five weeks, have a gestation of 21‑23 days, and typically give birth to 6‑12 pups. They can mate again within 24‑48 hours after parturition, enabling several litters each year.
How do white rats reproduce? - in detail
White rats reproduce sexually, following a well‑characterized mammalian pattern. Females reach sexual maturity at 5–7 weeks of age, marked by the onset of the estrous cycle, which lasts approximately 4–5 days. The cycle comprises proestrus, estrus, metestrus, and diestrus; estrus is the only phase when the female is receptive to a male.
Mating occurs when a male detects pheromonal cues from a female in estrus. Courtship involves sniffing, mounting, and intromission. Copulation typically lasts 30–60 seconds, and a single mating event can result in fertilization. Spermatozoa are stored in the female’s oviducts and travel to the oocytes within hours.
Fertilization takes place in the ampulla of the oviduct. The resulting zygote progresses to the uterus, where implantation occurs around day 5 post‑coitum. Gestation in white rats lasts 21–23 days. During this period, the placenta provides nutrients and hormonal support, while the mother exhibits nesting behavior, constructing a shallow depression lined with shredded material.
Litter size averages 6–12 pups, though extremes of 2–14 are reported. Newborns are altricial: hairless, eyes closed, and dependent on maternal milk. Pup weight at birth ranges from 3–5 g. The mother nurses the litter approximately every 2–3 hours, with milk composition changing from colostrum to mature milk by day 5.
Developmental milestones include eye opening at 14 days, ear unfolding at 10 days, and weaning at 21 days. By 4 weeks, juveniles attain adult body weight and can be separated for independent housing. Puberty in males occurs at 6–8 weeks, marked by the descent of testes and the emergence of mating behavior.
Reproductive performance is influenced by environmental factors such as photoperiod, temperature, diet, and population density. Optimal conditions—12 h light/12 h dark cycle, ambient temperature of 20–24 °C, and a protein‑rich diet—promote regular estrous cycles and maximal litter output.