Ensiling of maple leaves and its use in winter nutrition of mantled guereza ( Colobus guereza )

Young leaves are favored by mantled guereza (Colobus guereza) and the gastrointestinal tract of this species is well adapted to such a high fiber diet. Fresh maple leaves are often used in the diets for guereza in captivity but their use in winter feeding time is limited. The aim of the study was to evaluate the effect of additives on chemical composition and fermentation parameters of maple leaf silage, as well as inclusion of maple leaf silage in the diet for mantled guereza on feed and nutrient intake. Maple leaves were ensiled without additives (MLS), with a mixture of bacterial inoculants (MLS + BI) and with carrot additives (MLS + C). The chemical composition and fermentation parameters were determined in fresh and ensiled material. A group of seven mantled guerezas were fed a standard diet, and afterwards shifted to a diet with maple leaf silage (contained 20% of MLS; as fed). Each diet was fed for 7 days when the feed and nutrient intake were measured. The ensiling process did not change the concentration of most nutrients compared to the fresh material. The inclusion of leaf silage increased dry matter intake by guereza (125.3 vs. 163.3 g dry matter/day). Therefore, higher nutrient intake (crude protein, NDF, ADF) was observed when maple leaf silage was included in the diet. In conclusion, the ensiling process (even without additives) proved to be a good conservation method for maple leaves. Furthermore, inclusion of maple leaf silage in the winter diets for guereza, and possibly other folivorous primates, may increase dry matter and nutrients (particularly fiber) intake.