The influence of sward height on the mechanics of grazing in
steers and bulls
A. Mursan, T.P. Hughes, A.M. Nicol, T. Sugiura
Animal and Veterinary Sciences Group, Lincoln College,
Canterbury
Proceedings of the New Zealand Society of Animal Production.
1989, 49: 233-236
The relationships between sward height, bite dimensions and bite
weight for one-year-old Friesian steers and bulls were examined.
Eighteen turfs of uniform area of each of 3 pasture heights (5, 10, 15
cm) were cut from a ryegrass dominant sward in early spring and placed
in polystyrene boxes. Sward height was measured prior to grazing and
swards trimmed where necessary so that height in the surface horizon was
uniform. The turfs were offered over 3 days to 3 bulls and 3 steers in
a latin square design so that each animal had 20 bites of a turf of each
height daily. Turfs were weighed to the nearest 0.1g before and after
grazing. The height of grazed tillers was measured and all pasture was
then removed above this height. The turf was then reweighed. Bite
weight, depth, volume and area were then calculated for the steers and
bulls. There was no significant difference between bulls and steers in
bite dimensions. Sward height, which determines bite depth, appears to
be the major determinant of bite weight and consequently of daily
intake. The technique described has proved to be extremely useful in
the study of specific sward structures and their effect on intake.
Keywords: NZSAPAB;
Bulls; steers; turf; sward height; bite weight; bite dimension
Download abstract in text format
Last Updated 18-03-1997
