The effect of teeth condition on the intake of grazing sheep

Abstract

There is a real need to know what effect teeth have on grazing efficiency of sheep. The normal farming practice to cull ewes with teeth that are no longer considered useful, while this may be a sound practice, there is not enough evidence to justify or refute this practice. Most of the work recent years has been centred on the causes of wear in sheep's teeth, or on causes of "broken-mouth", but there has been very little work done on the effect of teeth on grazing intake of sheep.

This experiment was designed to measure the effect of teeth the intake of grazing ewes. Sheep with good, medium and poor teeth were run on long grass to measure the effect of age on intake, on short grass to measure the effect of age and teeth on intake. The three groups were also run on turnips, and fed barley and straw.

Intakes were measured by comparing the faecal O.M. outputs the groups, as faecal O.M. outputs were considered to give a more reliable estimate of intake differences, than D.O.M. or O.M. intakes. Faecal O.M. outputs were measured by the chromic oxide method, and D.O.M. and O.M. intakes by the use of the faecal O.M. outputs and the N% of the faecal O.M. to measure digestibility

All the literature on sheep's teeth has been reviewed, but brief review only of the techniques of intake measurement has been made, as these have been thoroughly reviewed recently. The factors affecting the intake of grazing sheep, such as the age of the sheep and pasture availability, are also reviewed as they are considered to be important in this experiment.