Ruminal behaviour of structural carbohydrates, non-structural 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 estimated in dairy cows using nylon bag incubations. Soluble fraction (starch, CP), undegradable fraction (NDF, CP), lag time (NDF) and rate of degradation of the insoluble but degradable fraction (NDF, starch, CP) were measured and 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 feeds and between soluble and insoluble fractions. It is concluded that such ratio's can be used to optimize the composition of concentrates with regard to rumen fermentation. (Abstract retrieved from CAB Abstracts by CABI’s permission)