Processing Matters in Nutrient-Matched Laboratory Diets for Mice-Energy and Nutrient Digestibility

Area of Science:

• Animal Nutrition
• Food Science
• Laboratory Animal Science

Background:

• Starch gelatinization is a key factor in carbohydrate digestibility, influenced by food processing methods.
• Laboratory rodent diets, though often marketed as identical, are available in different forms (extruded vs. pelleted) with varying starch gelatinization levels.

Purpose of the Study:

• To investigate the impact of diet processing (extruded vs. pelleted) on energy and nutrient digestibility in mice.
• To assess the consistency of laboratory animal diets across different batches.

Main Methods:

• Feeding C57BL/6 mice a standard maintenance diet in both extruded and pelleted forms.
• Analyzing the digestibility of organic matter, energy, and carbohydrates.
• Evaluating starch and total dietary fiber content variations between diet batches.

Main Results:

• Extruded diets resulted in significantly higher digestibility of organic matter, energy, and carbohydrates compared to pelleted diets.
• Replication revealed significant variations in starch and total dietary fiber content between batches of the same pelleted diet.

Conclusions:

• Diet processing significantly affects nutrient and energy digestibility in mice.
• Variability in laboratory animal diet composition and processing impacts experimental reproducibility, particularly in gastrointestinal and microbiome research.
• Starch gelatinization degree should be declared for laboratory animal diets, and batch-to-batch consistency is critical.