A comparative study of the apparent total tract digestibility of carbohydrates in Icelandic and Danish warmblood horses fed two different haylages and a concentrate consisting of sugar beet pulp and black oats.

This study compared the digestion of carbohydrates in Icelandic and Danish Warmblood horses eating different diets. The diets were composed of sugar beet pulp, black oats and haylage (either early or late cut). The results indicated that the maturity of the haylage and the type of horse breed both influenced the ability of these horses to extract nutrients from their diets.

Study Design and Methods

• The researchers used eight horses, four Icelandic (ICE) and four Danish Warmblood (DW), in a crossover study. This type of study design is when participants receive different treatments in random order, making it possible to compare the effects of multiple treatments in the same animals.
• The horses were given two treatment diets composed of sugar beet pulp, black oats, and either early cut or late cut haylage. Haylage is a type of horse feed similar to hay, but with more moisture.
• They analyzed the fibre content of the feed in terms of crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF), and dietary fibre (DF, which comprises non-starch polysaccharides and lignin).

Results and Findings

• The study found that as haylage matured, the levels of all types of fibre increased, while the amount of crude protein and sugars decreased.
• The maturity of the haylage (early vs. late cut) influenced the apparent total tract digestibility (ATTD) of various components of the horse diet. The early cut haylage led to a higher ATTD of dry matter, organic matter, energy, NDF, total NSP, DF, and CP.
• The breed of the horse also had an impact on ATTD, with Icelandic horses showing higher ATTD of CF, DF, and starch compared to Danish Warmblood horses.
• The diet also significantly affected several faecal parameters. Horses fed earlier cut haylage had more acidic faeces and higher concentrations of short-chain fatty acids, indicating higher fermentability of the diet.

Implications and Conclusions

• The research indicates that the time of haylage cut and the horse breed can both affect how well the horse can digest its food and extract nutrients.
• The study also validates the use of dietary fibre analysis method as a way to differentiate various fibre fractions and their digestibility in horse feeds over other traditional analysis methods.
• The results suggested that Icelandic horses may have a higher ATTD than Danish Warmbloods, but it was suggested that further research is needed to confirm this finding.