The effects of hazelnut hull on silage fermentation, aerobic stability and in vitro gas production of maize silage grown as a second crop

This study was designed to determine the effects of hazelnut hull supplementation on fermentation, microbiological structure, aerobic stability, cell wall components, and in vitro rumen gas production parameters of maize silage. In this study, the second crop maize was used as silage material (26,61% dry matter). It was chopped in 2 cm size and mixed with previously ground hazelnut hull. The mixture was ensiled in 1,5 L laboratory silos (Weck, Wehr-Oflingen, Germany). A total of 18 jars of silage, consisting of 2 treatments, 3 different opening periods (8th, 21st, 60th days of ensiling), and 3 parallels, were prepared as control silage without additives and silages containing hazelnut hull. Chemical and microbiological analyzes were carried out on the silages in all opening periods. The aerobic stability test was applied to the silages opened on the 60th day of ensiling for five days. Besides, the in vitro gas production values and in vitro nutrient digestibility of the silages were determined and protozoa count was performed in rumen fluid. Inclusion of hazelnut hull increased the silage dry matter, pH, crude ash, crude protein, crude cellulose, neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents (P<0,05) while reducing hemicellulose content in silages (P<0,05). Hazelnut hull additive reduced lactic acid, propionic acid, acetic acid and butyric acid contents in silages (P<0,05). The inclusion of hazelnut hull increased the lactobacilli population in the silages but it did not affect the yeast-mold population (P>0,05). The inclusion of hazelnut hull positively affected aerobic stability in silages (P<0,05). Hazelnut hull inclusion reduced in vitro gas production value, organic matter digestion, metabolic energy, net energy lactation values of corn silage (P<0,05) but increased the number of protozoa in the rumen (P<0,05). Keywords: Hazelnut hull, corn silage, fermentation, aerobic stability, in vitro gas production, protozoa