The Effect of Willow Tree (Salix Alba) Leafs Added at Different Levels to Some Roughages on In Vitro Digestibility and Methane Production

This study was carried out to investigate the effect of willow tree leafs (Salix alba) added at different levels (0 %, 10 %, 25 %, 50 %, 75 % and 100 %) to grass forage, wheat straw, alfalfa forage and maize silage on the in vitro methane production. Methane production after 24 h incubation of the roughages were measured by injection of the produced gas samples into a special apparatus connected to computer. Condensed tannin content of willow tree leafs was determined as 105 g/kg dry matter. The lowest methane production was determined in the groups of wheat straw added with 50 and 75% willow tree leafs as well as in the groups of alfa alfa hay and corn silage added with 75 % willow tree leafs (P<0.05). The lowest ammonia nitrogen level was observed for alfalfa forage in the treatment group containing 50 and 75 % willow tree leafs (P<0.001). However addition of willow tree leaves to wheat straw increased the ammonia nitrogen value in all treatment groups compared to control group (P<0,01). As a conclusion addition of the willow tree leaf to roughages decreased in vitro methane production. Metabolic energy value and in vitro dry matter digestibility of wheat straw were increased while these values were decreased in alfa alfa roughage and corn silage by addition of willow tree leaf. Further in vivo studies are required in order to determine the effect of willow tree leaf addition on animal performance