Determination of Chemical Composition and Degradability Coefficients of Salsola tomentosa in Different Growth Stages Using in situ Method

This study was conducted to determine the chemical composition and degradability characteristics of a pasture plant Salsola tomentosa by nylon bags method. The sampling was performed from the northern region of plain''s Gonabad city in three growth stages (vegetative، flowering and seeding). The samples dried in air، were milled and their chemical composition were determined. To determine the degradability of dry matter، protein، acid detergent fiber and neutral detergent fiber، two fistulated cows were used and degradation of samples were measured and calculated at 0، 2، 4، 8، 16، 24، 36، 48، 72 and 96 h. The results of this study showed that the highest of protein and organic matter percentage were 10. 34% and 76. 75% respectively in vegetative stage and there was statistically difference between growth difference stages. The highest amount of ash was observed in seeding stage (31. 9%). Advancing growth stage was associated with decreasing plant protein and increasing acid detergent fiber (ADF) and neutral detergent fiber (NDF). Dagradability of dry matter، crude protein، ADF and NDF were greater in vegetative stage as compared with other stages. Degradabilities of NDF،ADF and CP were decreased significantly as growth increased. The results of this study showed that with advancing of growth stage، concentration of CP decreased، and fiber content increased and degradabilities of CP، NDF and ADF were decreased significantly as growth increased