Abstract:

Nylon-bag technique was used to evaluate the disappearance rate and effective degradability of DM, OM, CP, NDF and ADF in six forages, meanwhile, the correlations were analyzed between degradation model parameters, effective degradability and forage nutrients. The results showed that: DM effective degradability of alfalfa powder was the highest in six forages，and there was no significant difference between annual ryegrass powder and alfalfa powder(P>0.05), but there were significant difference between alfalfa powder and in turn reduced alfalfa block, vicia atropurpurea, barley straw power, and setaria powder(P<0.01); CP effective degradability of alfalfa powder was the highest in six forages，and there were significant difference between alfalfa powder and in turn reduced alfalfa block, annual ryegrass powder, vicia atropurpurea, barley straw power, and setaria powder(P<0.01); Effective degradabilities of NDF and ADF of alfalfa powder was the highest in six forages，and there was no significant difference between alfalfa block and alfalfa powder(P>0.05), but there were significant difference between alfalfa powder and in turn reduced annual ryegrass powder, vicia atropurpurea, barley straw power, and setaria powder(P<0.01). Comprehensive determination of all the nutrition index, the nutritional value of six forages to Yunnan Yellow Cattle were: alfalfa powder > alfalfa block ≈ annual ryegrass powder > vicia atropurpurea > barley straw power > setaria powder. The parameters and effective degradability of forages degradation model had strong positive correlation with forage nutrient CP content, but had strong negative correlation with NDF and ADF contents.