What do white rats and mice eat? - briefly
White laboratory rats and common mice are omnivorous, thriving on a nutritionally balanced pellet or mash that includes grains, protein sources, vitamins, and minerals; they also accept occasional fresh fruits, vegetables, and small insects as supplemental treats.
What do white rats and mice eat? - in detail
White laboratory rodents require a balanced diet that supplies protein, energy, fiber, vitamins and minerals in proportions that support growth, reproduction and health.
Typical commercial pellets for albino rats contain 18–22 % protein, 4–6 % fat, 3–5 % fiber, and a calibrated mineral‑vitamin premix. The protein source is usually soy or casein; the fat component comes from vegetable oils; carbohydrates are supplied by wheat, corn or barley. Calcium and phosphorus are present at a ratio of approximately 1.2:1, and the feed includes trace elements such as zinc, copper, manganese and selenium, together with vitamins A, D3, E and the B‑complex group.
Mice receive a similar formulation, but with slightly higher protein (20–24 %) and lower fiber (2–3 %). The reduced fiber reflects the species’ smaller gastrointestinal capacity and lower bulk‑forming needs.
In addition to dry mash or pellet feed, rodents accept fresh foods that can be offered intermittently:
- Small pieces of fresh fruit (apple, banana, berries) – limited to 5 % of total intake to avoid excess sugar.
- Vegetables (carrot, broccoli, leafy greens) – provide additional vitamins and fiber.
- Lean cooked protein (hard‑boiled egg, low‑fat chicken) – useful for breeding females or during recovery from illness.
- Whole‑grain cereals or unsalted nuts – occasional energy boosters, not to exceed 2 % of diet.
Water must be available ad libitum, supplied via a bottle with a metal sipper tube to prevent contamination. Deionized or filtered water is preferred; chlorine‑free supplies reduce the risk of gastrointestinal irritation.
Nutrient requirements vary with life stage. Juvenile rats and mice need higher protein (up to 24 %) and calcium for skeletal development. Pregnant or lactating females require increased calories (approximately 20 % more) and additional calcium and vitamin D to support milk production. Aged individuals benefit from reduced fat content and added antioxidants (vitamin E, selenium) to mitigate oxidative stress.
Specialty diets exist for research purposes: high‑fat formulas for obesity studies, low‑protein regimens for renal investigations, and purified ingredient diets that eliminate plant‑derived phytoestrogens when hormonal control is critical.
Overall, a nutritionally complete pellet or mash, supplemented with limited fresh items and constant clean water, meets the dietary needs of white rats and mice under standard laboratory conditions.