What should newborn rats be fed? - briefly
Newborn rats require maternal milk or a commercially formulated rat milk replacer, administered by syringe every 2–3 hours. Transition to solid chow begins around day 21.
What should newborn rats be fed? - in detail
Neonatal rodents require a diet that mimics the composition of their mother's milk until they can transition to solid food. The primary source of nutrition is a commercially prepared milk replacer specifically formulated for rats. Such replacers contain the correct balance of protein (approximately 20 % of calories), fat (about 30 % of calories), lactose, and essential micronutrients, including calcium, phosphorus, vitamin D, and B‑complex vitamins. The solution should be reconstituted with sterile, warm water according to the manufacturer’s instructions, ensuring a temperature of 37 °C before feeding.
Feeding schedule:
- First 3 days: 0.2 ml per pup, administered every 2 hours, including nighttime.
- Days 4‑7: increase to 0.4 ml per pup, maintain 2‑hour intervals.
- Days 8‑14: raise to 0.8 ml per pup, feed every 3 hours.
- After day 14: gradually introduce solid chow while reducing milk volume.
Administration technique:
- Use a calibrated oral syringe with a soft, flexible tip to avoid damaging the delicate oral cavity.
- Hold the pup gently but securely, with the head slightly elevated.
- Deliver the milk slowly, allowing the animal to swallow before the next increment.
- Observe for signs of aspiration (coughing, choking) and adjust technique if needed.
Critical considerations:
- Sterility: prepare fresh solution daily; discard any leftover milk after 24 hours to prevent bacterial growth.
- Hydration: the milk replacer supplies adequate fluid; supplemental water is unnecessary until solid food is introduced.
- Weight monitoring: record pup weight daily; a gain of 1–2 g per day indicates proper nutrition.
- Transition to solid diet: introduce a high‑protein rodent chow mixed with a few drops of milk replacer around day 14, gradually increasing the proportion of solid food over a week.
If a commercial rat milk replacer is unavailable, a formula for mouse pups can be used as a temporary substitute, adjusting protein and fat concentrations to match rat requirements. Homemade mixtures are discouraged because they risk imbalanced nutrient ratios and contamination.