Authors: Hansen Tayler L, Chizek Elisabeth L, Zugay Olivia K, Miller Jessica M, Bobel Jill M, Chouinard Jessie W, Adkin Angie M, Skurupey Leigh Ann, Warren Lori K
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Coastal bermudagrass hay presents a fundamentally different digestive challenge to horses compared with cool-season alternatives, with dry matter digestibility declining to just 36% regardless of harvest maturity—roughly 40% lower than alfalfa and substantially below orchardgrass. Researchers fed five different hay types (alfalfa, orchardgrass, and Coastal bermudagrass at 4, 6, and 8 weeks of regrowth) to horses using cobalt-labelled and ytterbium-labelled fibre markers over 84-hour faecal collection periods to track both particulate and liquid digesta passage rates. Bermudagrass required significantly longer retention times—31.3 hours for particulate matter and 25.3 hours for liquid digesta—compared with orchardgrass and alfalfa (28.0 and 20.7 hours respectively), suggesting the forage's unique fibre structure demands extended gastrointestinal processing. The poor digestibility and prolonged passage kinetics remained consistent across all three harvest maturities, indicating that delaying cutting does not improve nutritional value in this species. For practitioners formulating rations around warm-season grasses, these findings underscore the importance of supplementary protein and energy sources when bermudagrass constitutes a significant portion of the diet, whilst highlighting the need for further research into how fibre chemistry influences digestive efficiency and potential gut health implications of extended retention times.
Read the full abstract on PubMed
Practical Takeaways
- •Warm-season grasses like Coastal bermudagrass have substantially lower digestibility than alfalfa or orchardgrass, requiring consideration in ration formulation and feed quality assessment
- •Longer digesta retention time with bermudagrass may increase risk of impaction and other digestive disorders—monitor water intake and exercise accordingly
- •Harvest maturity of bermudagrass (4 vs 6 vs 8 weeks) does not significantly improve digestibility, so earlier harvest timing may offer no digestive advantage
Key Findings
- •Alfalfa had the greatest dry matter digestibility at 62.1%, while Coastal bermudagrass at 6 and 8 weeks of regrowth had the lowest at 36.0-36.8%
- •Coastal bermudagrass had significantly longer mean retention time (31.3 h particulate, 25.3 h liquid) compared to orchardgrass (28.0 h) and alfalfa (20.7 h)
- •Differences in digestive variables between forage types are attributable to fiber physiochemical properties rather than maturity alone