| The effects of barley grain on rate of in situ degradation, in vivo digestibility and rate and efficiency of gain of steers were determined using ten lots of barley grain. The barley samples varied with respect to volume weight (VW), crude protein (CP), acid detergent fibre (ADF), kernel hardness (KH), and in situ dry matter (DM) degradability after 0, 4, 8, 12, and 24 h. There were differences in total tract organic matter digestibility between barley samples and between two-row and six-row barley. The digestible energy (DE) content also varied between barley samples and between two-row and six-row barley. No differences in DM intake, average daily gain (ADG), feed DM:gain ratio, or carcass characteristics were detected between steers fed these ten different samples of barley in diets containing 85.5% barley grain. Similarly, no differences in these parameters were detected between steers fed two-row, six-row or hulless barley, or between steers fed malting or feed barley. Feed ratios were related to 24 hour in situ degradability of ground grain DM and to 24 hour in situ degradability of rolled (cracked) grain DM. Significant relationships were detected between the percentage of animals which bloated and CP, ADF, VW, and in situ DM degradability after 12 h. It was concluded that large differences in the feeding value of two-row vs. six-row, or malting vs. feed barley grains of similar volume weight are not to be expected when the grains are included in feedlot diets containing adequate protein and other nutrients. (Abstract shortened by UMI.)... |
