Authors: Tassone Sonia, Renna Manuela, Barbera Salvatore, Valle Emanuela, Fortina Riccardo
Journal: Journal of equine veterinary science
Summary
# Editorial Summary In vitro digestibility testing using the DaisyII Incubator has proven valuable for equine nutrition research, yet comparable validation data for donkeys—which have distinct digestive physiology—remained absent until now. Tassone and colleagues evaluated whether donkey faecal inoculum could reliably measure dry matter and fibre digestibility of seven common feedstuffs (alfalfa, bromegrass, ryegrass, timothy, wheat bran, wheat straw, and barley) across 1-, 2-, 3-, and 4-week collection periods, with duplicate samples incubated for 30, 48, 60, and 72 hours. All digestibility parameters increased significantly over the 72-hour incubation window; at 72 hours, dry matter digestibility showed good repeatability (2.7%) and reproducibility (5.0%), whilst true dry matter digestibility performed excellently with 1.6% and 3.9% values respectively, though neutral detergent fibre digestibility proved less consistent (4.5% and 10.4%). The method's reliability at 72 hours makes it suitable for routine donkey nutrition work, though practitioners should note reduced precision for fibre-specific predictions and recognise this as a laboratory technique rather than a substitute for in vivo trials when precision is critical.
Read the full abstract on PubMed
Practical Takeaways
- •A validated method now exists for evaluating feed digestibility in donkeys using readily available fecal material, enabling more accurate nutritional assessment specific to donkey requirements
- •For practical feed evaluation purposes, 72 hours of incubation is optimal for consistent results, though NDFD measurements show greater variability and may require larger sample sizes
- •This methodology allows equine nutritionists and donkey owners to better tailor feed selections and rations by directly testing digestibility of specific feedstuffs for donkeys rather than relying on horse or cattle data
Key Findings
- •In vitro digestibility parameters (DMD, IVTD, NDFD) using donkey fecal inoculum significantly increased from 30 to 72 hours of incubation
- •At 72 hours incubation, DMD showed within-laboratory repeatability of 2.7% and reproducibility of 5.0%
- •IVTD demonstrated better repeatability (1.6%) and reproducibility (3.9%) compared to NDFD (4.5% and 10.4%, respectively)
- •The DaisyII Incubator method is suitable for measuring digestibility of common donkey feedstuffs using donkey feces as microbial inoculum