Use of in vitro gas production technique to compare nutritive value of quackgrass and Alfalfa for Ruminants

The objective of this study, was to assess the nutritive value of two forage species include Alfalfa (ALF) and Quackgrass (QCK) grown in Iran by using the chemical composition, in vitro gas production kinetics, Organic Matter Digestibility (OMD) and Metabolisable Energy (ME) contents. Rrumen mixed microbe inoculums were taken from two fistulated Gezel rams. Samples of forages were incubated with rumen fluid to determine gas production. Gas productions were measured at 2, 4, 6, 8, 12, 24, 48, 72 and 96 h. No significant differences were found between Organic Matter (OM), Ether Extract (EE), ash and Acid Detergent fiber (ADL) contents of experimental forages, although the differences for Dry Matter (DM), Crude Protein (CP), Crude Fiber (CF), Neutral Detergent Fiber (NDF), ADF and Gross Energy (GE) were significant (p<0.01). Gas production at all incubation times and gas production constants (a, b, c and a + b) were significantly (p<0.01) higher in ALF hay. The OMD and ME for ALF and QCK hays were 71.2, 43.45% and 10.96, 6.58 MJ per Kg DM, respectively. Under the climatic conditions of the 2005 growing season, the nutritive value of ALF hay was higher to that of QCK hay, because of lower NDF, greater cell content, OMD and ME.