نوع مقاله : مقاله پژوهشی
1 گروه علوم دامی دانشگاه ارومیه
2 استادگروه علوم دامی/ دانشگاه ارومیه
3 گروه تحقیق و توسعه شرکت دانش بنیان کیمیادانش الوند
عنوان مقاله [English]
Background and objectives: Lack of green fodder and high cost of concentrated feed are among the limiting factors in the feed and livestock production industry. Therefore, ruminants use crop residues for feeding. These agricultural residues contain high cell wall content and low amounts of protein and metabolizable energy. To improve the quality of these by-products, various processes are used, including biological processes. Processing of straws using fungi has been shown to improve the nutritional value and degradability of their cell wall compounds. Therefore, this study was conducted to investigate the effect of Aspergillus oriza on chemical composition, volume of gas produced, degradability and the amount of volatile fatty acids produced by wheat straw.
Materials and methods: In this study, two methods of liquid culture and solid culture of fungus were used to process wheat straw. The fungal contents were transferred to jars containing sterilized wheat straw and stored at 26 ° C for 25 days. The contents of the jars were dried and ground after 25 days and used for further experiments such as chemical composition, gas volume, dry matter degradability, Neutral Detergent Fiber and the amount of volatile fatty acids produced.
Results: Processing with Aspergillus oryzae reduced dry matter, organic matter, Neutral Detergent Fiber and Indigestible neutral detergent fibers and was able to significantly increase the amount of protein so that solid culture increased protein by 2.94%. It was 5.86 percent. Processing of wheat straw by solid and liquid culture methods increased the volume of gas produced during 144 hours of incubation from 267.92 to 327.50 and 338.98 ml per gram of dry matter, respectively. Processing was able to increase the amount of Metabolisable energy and the amount of dry matter digestibility of straw and the highest amount of Metabolisable energy was observed in wheat straw processed by solid culture. The effective degradability of dry matter increased at the level of 2% passing through the rumen in wheat straw processed by solid culture method. Nutritional value index increased in both treatments compared to the control group. The degradability of Neutral Detergent Fiber was not affected by processing in solid culture but liquid culture reduced the degradability. Processing by both methods increased the total amount of volatile fatty acids produced and ammonia nitrogen of wheat straw.
Conclusion: Processing wheat straw by liquid and solid culture of Aspergillus oryzae improved some of the nutritional components of this crop and affected the amount of Neutral Detergent Fiber as well as insoluble Neutral Detergent Fiber. It has the ability to digest some lignin-cellulosic compounds in the cell wall, and since solid culture had significant beneficial effects compared to liquid culture, In general, it can be said that extracting the enzymatic complex of Aspergillus oryzae cultivar grown in solid culture medium and injecting it into wheat straw improves the nutritional value of straw.