RUMINAL BEHAVIOR OF STRUCTURAL CARBOHYDRATES, NONSTRUCTURAL CARBOHYDRATES AND CRUDE PROTEIN FROM CONCENTRATE INGREDIENTS IN DAIRY-COWS

Ruminal degradation characteristics of Neutral Detergent Fibre (NDF), starch and crude protein (CP) in concentrate ingredients were determined in dairy cows by means of nylon bag incubations. Measured characteristics were soluble fraction (starch, CP), undegradable fraction (NDF, CP), lag time (NDF) and rate of degradation of the insoluble but degradable fraction (NDF, starch, CP). All measured characteristics showed large variation. Based on measured and partly estimated characteristics ratio's were calculated between total rumen available CP and carbohydrates, between soluble CP and soluble carbohydrates and between insoluble rumen available CP and insoluble rumen available carbohydrates. Ratio's varied largely between feedstuffs and between soluble and insoluble fractions. It was concluded that such ratio's can be used to optimize the composition of concentrates with regard to rumen fermentation.