1998 Volume 43 Issue 4 Pages 430-438
Fibrous, degradable and physical characters in 14 varieties of orchardgrass (Dactylis glomerata L.) were evaluated for 4 years in connection with the study on their palatability measured by Holstein heifers. Relationship between these characters in varieties and their palatability were investigated throughout the growing seasons. NDF and ADF content were negatively correlated with palatability at the heading stage in spring and at the regrowth in summer, respectively. As for degradable characters, cellulase degradability (a+b), instantly soluble fraction (a), insoluble but potentially degradable fraction (b) and the rate constant (c) of degradable fraction were determined by the φRSKOV'S equation: Y=a+b (1-e^<-ct>), respectively. Significant correlation coefficients between these degradable characters and palatability were not obtained throughout the growing seasons; it indicates that breeding for the improvement of both palatability and degradability and/or degradable characters in orchardgrass might be possible. As for physical characters, such as leaf tension and compression load, grinding energy and viscoelastic parameters were related with degradability in seasonal changes. But on the whole, they were not significantly correlated with palatability.
