"Graze" is a user-friendly, Microsoft Windows 95/NT program for analysing jaw movement recordings taken with the "IGER Behaviour Recorder" [2, 3]. The program displays a plot of the jaw movement amplitude (vertical axis) against time (horizontal axis). Various scales for the horizontal (time) axis can be selected, allowing the user to zoom in and out of the recording. Individual jaw movements can be automatically identified using amplitude and frequency criteria specified by the user. Bouts of jaw movements can then be analysed, and are automatically identified as either grazing or ruminating. If, when processing a bout, the program fails to recognise any jaw movement patterns associated with eating and ruminating, the bout is marked as undetermined. Identified jaw movements and bouts of behaviour are superimposed on the jaw data display. This allows the user to check that the program has correctly identified both jaw movements and bout behaviours. Jaw movement identification criteria can then be changed, if required, to improve the accuracy of automatic identification. Individual bouts of behaviour can also be edited by the user, either to correct any mistakes in the automatic interpretation, or to remove any bouts which are not of interest to the user e.g. because they are outside the experimental measurement period. Behaviours other than eating and ruminating (such as 'drinking' or 'eating supplements') can also be identified and marked by the user. The bout information can be saved in a separate Bout Mark file. This file can then be read back into 'Graze' should the user need to re-analyse a file subsequently. Finally, the user can perform a 'bout analysis', which discriminates between bites and chews during eating, and generates a 'Results' file. This file summarises information for each bout of behaviour, and can be saved as either a text file or as a 'CSV' ('comma separated values') file that can be read directly into a spreadsheet (e.g. Microsoft Excel).

The identification algorithm [4] was developed for and has been validated for use with cattle jaw movement recordings [1]. Initial results suggest that the cattle analysis algorithm can also be used with sheep recordings, although this has yet to be fully validated.

References

1. Champion, R.A.; Rutter, S.M.; Orr, R.J. (1997). Distinguishing bites and chews in recordings of the grazing jaw movements of cattle. Proceedings of the 5th Research Conference of the British Grassland Society (Seale-Hayne, Newton Abbot, UK, 8-10 September 1997).
2. Rutter, S.M.; Champion, R.A.; Penning, P.D. (1996). A system to record automatically foraging behaviour in free-ranging herbivores. Measuring Behaviour ’96 (Utrecht, The Netherlands, 16-18 October 1996), 88.
3. Rutter, S.M.; Champion, R.A.; Penning, P.D. (1997). An automatic system to record foraging behaviour in free-ranging ruminants. Applied Animal Behaviour Science, 54, 185-195.
4. Rutter, S.M.; Penning, P.D.; Rook, A.J.; Orr, R.J.; Gibb, M.J.; Champion, R.A.; Huckle, C. (1997). An algorithm for the automatic processing of recordings of foraging behaviour by cattle. In: P. Hemsworth and M. Spinka (eds.), Proceedings of the 31st International Congress of the International Society for Applied Ethology (Prague, 13-16 August 1997).