عنوان	فراسنجه‌های تخمیر و قابلیت هضم مواد مغذی جیره‌های حاوی سطوح مختلف باگاس نیشکر در شرایط آزمایشگاه
نوع پژوهش	پایان نامه
کلیدواژه‌ها	.
چکیده	The current study aimed to investigate the effect of diets containing different levels of stored or fresh sugarcan bagasse as a substitute for wheat straw on chemical composition, fermentation parameters and digestibility of dry matter (DM) and organic matter (OM) by gas production method. Bagasse samples were obtained from a sugarcane factory located in Khuzestan province and wheat straw samples were obtained from agricultural fields in Ilam province. The stored bagasse had been hold in the warehouse for one year. The results showed that wheat straw had higher content of DM, crude protein (CP) and ash, and lower content of OM, acid detergent fiber (ADF) and lignin compared to fresh or stored bagasse (P˂0.05). The content of DM, OM, ADF, CP and ash did not differ significantly between stored and fresh bagasse (P<0.05), but the lignin content in fresh bagasse was lower than stored bagasse (P˂0.05). The digestibility of DM and OM in wheat straw was higher compared to stored or fresh bagasse (P<0.05), but the digestibility of DM and OM in stored and fresh bagasse were not significantly different (P<0.05). Gas production after 24 h incubation was higher in wheat straw than stored or fresh bagasse (P<0.05), but no significant difference was observed between stored and fresh bagasse (P<0.05). In diets containing different levels of stored bagasse and wheat straw, the highest content of dry matter and ash and the lowest content of organic matter and acidic detergent fiber were observed in diet containing 30% wheat straw (P˂0.05). Crude protein content, ADF, lignin, 24 h gas production, methane production, dissociation factor, microbial mass production, efficiency of microbial mass production and digestibility of DM and OM are affected by diets containing different levels of stored bagasse (P<0.05), but the level of 30% bagasse caused a numerical decrease in digestibility of DM (P=0.07) and OM (P=0.08) compared to its lower levels. Gas production after 24 h incubation and OM digestibility in diets containing different levels of fresh bagasse and wheat straw had significant difference, so that the lowest 24 h gas production and OM digestibility were observed in diet containing 30% fresh bagasse (P<0.05). Ortogonal comparisons showed that the content of DM and ADF in the diet containing 30% stored or fresh bagasse was significantly different (P˂0.05). In general, digestibility of DM and OM was not significantly different between the experimental diets, but addition of 30% bagasse to diets caused a numerical decrease in the digestibility of DM and OM compared to its lower levels. So, it can be suggested to add 22.5% of bagasse instead of wheat straw in the ration of adult sheep.
پژوهشگران	فرشید فتاح نیا (استاد راهنما)، محسن بهزادی (دانشجو)، محمد شمس الهی (استاد مشاور)