نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده علوم دامی وشیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری (SANRU)، مازندران، ایران.
2 گروه علوم دامی، دانشکده علوم دامی و آبزیپروری، دانشگاه علوم کشاورزی و منابع طبیعی ساری (SANRU)، مازندران، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: The increasing price of animal feed and the limited availability of arable land make it necessary to explore alternative sources of animal feed. In Asia, the most abundant agricultural by-product is rice bran. However, its use on a large scale has been limited due to the lack of awareness among farmers and the lack of access to nutritional information on the bran of local rice varieties. The nature and chemical composition of rice bran depend on the variety, milling system, and type of processing. These differences can affect the degradability, gas production, and nutrient digestibility, and consequently, the feeding behaviors and performance of livestock. Shiroodi and Hashemi rice varieties are cultivated in abundance in Gilan and Mazandaran, and the bran of these varieties is available in these regions. Therefore, the aim of this experiment was to compare wheat bran with rice bran (varieties Shiroodi and Tarom Hashemi) and a mixture of these brans in terms of chemical composition, ruminal degradability, gas production parameters and estimation of digestibility.
Materials and Methods: This experiment was conducted in a completely randomized design using 3 fistulated Zel breed sheep with a mean weight of about 41 kg and a mean age of about 15 months, with 6 times and 5 replications at the research farm of Sari University of Agriculture and Natural Resources. The experimental treatments included 1) wheat bran, 2) rice bran of Shiroodi variety, 3) rice bran of Tarom Hashemi variety, 4) a mixture of rice bran of Shiroodi and Tarom Hashemi varieties, 5) a mixture of wheat bran and rice bran of Shiroodi variety and 6) a mixture of wheat bran and rice bran of Tarom Hashemi variety. The chemical compositions of processed rice bran (without oil) and wheat bran were measured according to standard methods. To determine the gas production, the volume of gas produced by the experimental treatments was recorded at times 0, 2, 4, 6, 8, 12, 24, 36, 48, 72 and 96 hours, and the gas production potential and estimated gas production parameters were calculated from the volume of gas produced based on 200 mg of dry matter over 24 hours. The dry matter and crude protein degradability parameters were determined by the nylon bag method after 0, 2, 4, 6, 12, 24, 36, 48, 72 and 96 hours. The effective degradability of the samples was also calculated at a passage rate of 0.02, 0.05, 0.08.
Results: Rice bran in both varieties had higher DM, ash, ADF, NFC, starch, lignin, and silica (P=0.0001) and lower OM, CP, EE (P=0.0001) and NDF (P=0.0033) than wheat bran. Organic matter and crude protein in Shirodi rice bran were higher than Tarom Hashemi rice bran, and its silica was lower. The gas production potential in treatments containing rice bran, especially the bran of the Tarom Hashemi variety, was significantly reduced (P=0.0001). Constant rate of degradation in rice bran treatments was significantly reduced (P=0.0148), although in the mixed treatments of wheat bran and rice bran, it did not show a significant difference with the wheat bran treatment. Gas production parameters including digestible organic matter, metabolizable energy, short chain fatty acids and microbial mass were significantly reduced in treatments containing rice bran, especially the Tarom Hashemi variety, compared to wheat bran (P=0.0001). Of the degradability parameters, only the rapidly degraded fraction was reduced in rice bran treatments compared to wheat bran (P<0.05). Other degradability parameters of dry matter and crude protein did not differ significantly between the experimental treatments.
Conclusion: Chemical compounds can affect the quality of rice bran and gas production and degradability parameters.
کلیدواژهها [English]
)