The establishment of faecal nitrogen—digestibility regressions for animals grazing irrigated pasture

Abstract

A regression for feed-to-faeces ratio on faecal nitrogen percentage was formulated from trials in which perennial irrigated pasture cut to ground level was fed to cattle and sheep at various times over several years.Similar data derived from ‘top’ (mainly leaf) and ‘bottom’ (mainly stem) cuts of a spring and of an autumn stand of pasture from the same vicinity did not conform with the ‘whole’ cut relationship and the three regressions which were established were heterogeneous.It is suggested that due to selectivity, the application to grazing animals of a regression derived from pasture cut to ground level may result in considerable error.