Risiko Gras - Realität oder übertriebene Befürchtung

Risk factor grass - Reality or exaggerated fear?

Coenen M, Vervuert I

DOI: 10.21836/PEM20020605
Jahr: 2002
Volume: 18
Ausgabe: 6
Seiten: 544-546

Grass as well as hay contain up to ~600 g different carbohydrates (CH) per kg dry matter (DM). Characteristically is that they need to be digested by microbial activity, but different between the CH is the dynamic in microbial fermentation per unit of time. In contrast to cellulose a rapid microbial break down is attributed to starch, oligosaccarides, mucin, pectin and polysaccarides (also summarized as soluble fibres). A high concentration of those CH in fresh lush pasture is related to the occurence of laminitis particular at the onset of the grazing season. A key position in the pathogenesis of laminits is considered to a marked change in the bacterial community in the hindgut and enteral acidosis, mainly in the caecum. Residues and metabolites of bacterial origin are absorbed and can induce damages in extraenteral tissues like the activation of metalloproteinases in the lamellar tissues. In that context the fructanes (polysaccharides consisting of fructose) are suggested to be of special interest. In experiments - in vitro and in vivo - is confirmed that high amounts of fructanes (750 g/100 kg body weight as a single dose; Pollitt und van Eps 02) induce changes in bacteria, caecal acidosis and laminitis. Common grasses contain up to 100 g fructanes/kg DM; but in dependance on saison up to 400 g fructanes/kg DM were found in specific breeds of rye grass. That suggests, a temporary critical high fructane intake on pasture which is entyped by those grasses can be occur. A careful adaptation of horses to fresh, lush pature and a calculated organisation of pasturing for those horses likely to be affected by laminitis are adeaquate measures to minimize the risk for that disease.