Comparative analysis of the energy values of oat hay, tall fescue, annual ryegrass, and barnyard millet using in vivo digestibility results and predicted values

Accurate measurements of feed energy values have a positive effect on the control of feed intake for animals, the formation of prices, and on economic profits. However, few studies have attempted to measure the energy values of domestic roughages and to validate an energy value prediction model. The purpose of this study is to build a database through measurements of the nutrient digestibility and digestible energy results of roughages used in Korea and to evaluate the domestic applicability of the National Research Council (NRC) estimation model. Oat hay, annual ryegrass, tall fescue, barnyard millet, and concentrates for beef cattle were used in the test. As a result of an in vivo digestibility trial, the total digestible nutrients (TDN) of oat hay, annual ryegrass, tall fescue, and barnyard millet were found to be 68.73, 55.02, 55.71, and 52.89%, respectively. As a result of comparing the estimated values using the NRC equation with the in vivo results, there was a difference of 3.55 to 6.84%P in the TDN. Inferred from this result, it is considered that TDN calculations using the NRC equation can be reasonable for the test feeds used in this study. These results can be utilized when revising the Korean Standard Tables of Feed Composition, which provides a comprehensive overview of Korean feed.