مطالعه ترکیبات شیمیایی و تخمیرپذیری آزمایشگاهی برخی از ارقام جو و لاینهای موتانت پنبه و گلرنگ

Abstract

Introduction By the end of the fourth development plan, annual grain shortages and protein meal for animal feed were 807 and 795 thousand tones, respectively. In the first nine months of 2014, an average of 1187 and 1865 thousand tons of protein meals were imported to the country. In recent years, due to the lack of water, salinity of water and soils, crop production has shown a significant decline. So, one of the suggestions in this regards is creation of new varieties with properties of higher production and resistant to environmental stresses. Fortunately, a lot of efforts in the country and especially in Nuclear Science and Technology Research Institute have been down for introducing different varieties of crop which is resistant against environmental stress. In most of these studies gamma ray has been used as a mutagenesis to create the lines and new varieties. Part of this research has led to introduce of the barley cultivar, Roddasht, and some lines of safflower, cottonseed and other crop species. Unfortunately, nutritional and digestive value of seed of these new cultivar and lines are not known for animals in line with their introduction. The aim of this study was to test the chemical composition, fermentation characteristic, digestible organic matter, metabolisable energy, VFA production and protein properties of barley (variety Roddasht) and mutant lines of safflower and cottonseed. Materials and Methods Cultivar of barley (Roddasht) and mutant lines of cottonseed and safflower were grown at research field of Nuclear Agriculture Research School. These cultivar and mutant lines were achieved via mutation breeding process of their parent's cultivare (i.e. Valfajr (Barley), Varamin (Cotton) and Zarghan (Safflower), respectively). A 1 kg sample (seed) of each was used in this study. All samples were ground through 2 mm screen (Retsch Cutting Mill, Retschmule, Germany) and used for subsequent analyses. The samples were analyzed in duplicate for crude protein (CP; kjeltel auto 1300, Foss, Denmark), and organic matter (OM). Neutral detergent fiber (NDF) and acid detergent fiber were determined. Gas production (GP) test was performed. Approximately 200 mg of dry matter (DM) of each treatment was placed in 100 ml syringes (four replicates) and 30 ml of incubation medium was then added to them. Gas production (GP) test was performed for three consecutive weeks. Rumen fluid was collected from the three cannulated sheep and squeezed through four layers of cheese cloth. Gas production was measured at 2, 4, 6, 8, 12, 24, 48, 72 and 96 h and a set of appropriate blanks was included. Gas produced from each treatment was calculated by subtracting the produced gas form gas produced in a control blank. Metabolisable energy, digestible organic matter and volatile fatty acids were estimated via available equations. Protein of seeds was extracted using Tris-HCl method. Extracted proteins were run on SDS-Pages and the protein lanes were stained with coomassie blue dye. Results and Discussion No significant differences were observed in chemical composition of mutant lines of cottonseed and safflower compared to their parental lines. Barley cultivar, Roddasht, had a lower (P<0.01) OM and CP compared to Valfajr. There were no significant differences of NDF and ADF between barley cultivars. Roddasht cultivar had a higher (P<0.01) volume of produced gas at 8 and 12 h of incubation in comparison with Valfajr. Valfajr barley had a lower (P<0.01) rate of fermentation than Roddasht. There were no significant differences of produced gas volume and rate between safflower and cottonseed cultivars compared to their mutants. There were no differences of digestible organic matter, volatile fatty acids and metabolisable energy of cultivar and mutants lines in comparison with their parents. Study of seed proteins by SDS-Page of barley, cottonseed and safflower didn’t show any differences between parents and their mutants. Conclusion Among studied cultivars and lines of barley, cottonseed and safflower the mutant of Roddasht had a lower OM and CP compared to Valfajr. The rapid rate of fermentation of Roddasht cultivar could contributes to some nutritional and health problems such as acidosis in ruminants. It can be concluded that barley cultivar, Valfajr, with higher content of crude protein and lower rate of fermentation might be recommended in ruminant feeding. No significant differences were observed in chemical composition and fermentation properties of mutant lines of cottonseed and safflower compared to their parental lines.