اثر افزودنی‌های مختلف بر کیفیت تخمیر سیلوی ارزن در شرایط آزمایشگاهی

The objective of this study was to evaluate the characteristics of millet silage prepared in laboratorial mini silos and to determine the effects of additives on its fermentation quality. Whole millet (Panicum milliaceum) was harvested at milk and soft-dough stages of maturity, left untreated or treated with ground barely, molasses, formic acid, lactic acid producing bacteria, and combination of molasses plus inoculant, and were ensiled in a completely randomized design in 2×6 factorial arrangement. Stage of maturity had no significant effect on NDF and ADF, buffering capacity, residual water soluble carbohydrate, acid detergent insoluble nitrogen, ammonia nitrogen and in vitro dry and organic matter digestibility however, values for dry matter, crude protein and pH were significantly different. Loss of dry matter, elevated NH3-N (24% of total nitrogen) and increased butyric and acetic acid levels (.2 and 1.33% DM, respectively) in control silage indicated clostridial fermentation. Between treatments, the lowest NH3-N was observed for silages treated with formic acid. Molasses and molasses plus inoculant produced higher lactic acid and lower butyric acid. Higher in vitro dry matter and organic matter digestibility showed positive effects of additive usage compared to control group. Addition of molasses and molasses plus inoculant resulted in higher in vitro dry matter digestibility (63.1 and 64.3 %, respectively), but no significant differences were observed between barely, formic acid and inoculant treated silages. Results of this study clearly showed the need for adding a source of water soluble carbohydrates to millet in order to obtain a good quality silage. Also inoculation of lactic acid bacteria does not necessarily promote homolactic fermentation if insufficient amounts of water soluble carbohydrates are presented.