Rumen nitrate metabolism and the changes occurring in the composition of the rumen volatile fatty acids of grazing sheep

摘要

Adult sheep and weaned lambs grazing ryegrass and clover pasture, and sampled at approximately monthly intervals, exhibited marked variations in the molecular percentage composition of the individual rumen volatile fatty acids. These variations were characterised by comparatively large changes in the percentage of acetic acid and compensatory changes in an inverse direction in the percentages of propionic and, to a smaller extent, n-butyric and the branchedchain acids.