How much food can be given to a rat? - briefly
A typical adult rat consumes roughly 3–5 g of standard rodent chow daily, equivalent to about 5–10 % of its body weight. Adjust portions based on age, activity level, and diet composition to avoid under‑ or over‑feeding.
How much food can be given to a rat? - in detail
Rats weighing 250–300 g require roughly 15 kcal per 100 g of body mass each day. This translates to an intake of 37–45 kcal for an adult of average size. Standard rodent chow provides about 3.3 kcal per gram, so a typical adult should receive 11–14 g of dry pellets daily.
Juvenile rats (under 60 days) have higher metabolic rates; they need 20–25 kcal per 100 g, equivalent to 12–15 g of chow for a 150‑g pup.
When supplementing with fresh foods, adjust the dry‑feed portion to keep total calories within the target range. Approximate caloric values for common additions are:
- Cooked wheat germ: 3.6 kcal g⁻¹
- Fresh fruits (apple, banana): 0.5–0.9 kcal g⁻¹
- Vegetables (carrot, broccoli): 0.2–0.4 kcal g⁻¹
A practical schedule:
- Provide measured dry pellets (11–14 g for adults) in the morning.
- Offer 1–2 g of fresh supplement in the afternoon, ensuring the combined caloric load does not exceed the calculated daily requirement.
Adjustments are necessary for:
- Increased activity (e.g., wheel running) – add 10–15 % of the base amount.
- Pregnancy or lactation – increase by 20–30 % to support growth and milk production.
- Illness or weight loss – reduce portions gradually while monitoring body condition.
Water must be available ad libitum; dehydration can skew intake measurements.
Regular weighing (weekly) allows fine‑tuning of portions. Maintaining the prescribed caloric range promotes stable body weight, optimal growth, and reliable experimental outcomes.