What do laboratory rats eat? - briefly
Laboratory rats receive a nutritionally balanced pellet chow designed to meet their protein, vitamin, and mineral needs, with water available at all times. Occasionally, small amounts of fruit, vegetables, or grains are added as enrichment, but they supplement rather than replace the primary diet.
What do laboratory rats eat? - in detail
Laboratory rodents receive a nutritionally balanced, commercially produced pelleted chow that meets the species‑specific requirements for protein, energy, fiber, vitamins, and minerals. The standard formula typically contains 18–20 % protein, 4–5 % fat, 4–5 % crude fiber, and a calibrated mix of micronutrients such as vitamin A, D3, E, B‑complex, calcium, phosphorus, magnesium, zinc, and iron. Ingredients commonly include corn, wheat, soy, and alfalfa, processed to ensure homogeneity and sterility.
Water is supplied ad libitum through calibrated bottles that prevent contamination. The fluid is usually deionized or filtered, with occasional addition of electrolytes for specific experimental protocols.
Supplementary feed items may be introduced for particular study designs:
- High‑fat diet: increased lipid content (≈45 % kcal from fat) using lard or vegetable oil, reduced carbohydrate proportion.
- Low‑protein diet: protein reduced to 5–8 % to model malnutrition or renal stress.
- High‑sugar diet: added sucrose or fructose to induce metabolic syndrome.
- Ketogenic diet: high fat, low carbohydrate, moderate protein to examine neuroprotective effects.
- Palatable treats: small portions of fruit puree, gelatin, or flavored pellets used for behavioral conditioning or to motivate performance in operant tasks.
Feeding schedules are generally continuous (ad libitum) to maintain stable body weight, but some protocols impose restricted access (e.g., 2–4 h per day) to control caloric intake or synchronize circadian rhythms. Intake is measured by weighing food hoppers before and after a set period, allowing precise calculation of daily consumption in grams and kilocalories.
Quality control measures include batch testing for nutrient composition, microbial load, and mycotoxin presence. Certified manufacturers provide certificates of analysis, and laboratories often perform independent verification to ensure consistency across experimental cohorts.
When special diets are required, researchers select formulations from established suppliers (e.g., Purina LabDiet, Harlan Teklad) that offer predefined compositions and detailed nutrient profiles, facilitating reproducibility and comparative analysis across studies.