1. The relationships between foraging behaviour, incisor arcade breadt
h and body mass were described for sheep and goats grazing from swards
of sown grass at two sward surface heights. 2. variation in bite mass
was related to incisor arcade breadth more closely than to body mass.
3. Bite area scaled as the square of the incisor arcade breadth and w
as smaller on the Tall sward height treatment. 4. Sheep had greater bi
te masses than did goats but goats had a higher bite rate than sheep a
nd as a consequence there was little difference in short-term intake r
ate between the species. 5. Young animals of both species had smaller
bite masses and intake rates than did mature animals. However, when ex
pressed relative to body mass there were no significant differences in
bite mass between maturity classes. 6. The results of the current stu
dy confirm that the size of the incisor arcade is a direct determinant
of bite dimensions and a driving variable for intake rate in grazing
ruminants.