Discriminant Analysis of Patterns of Jaw Movement During Rumination and Eating in a Cow
Titel:
Discriminant Analysis of Patterns of Jaw Movement During Rumination and Eating in a Cow
Auteur:
Schleisner, Christine Nørgaard, Peder Hansen, Hanne H.
Verschenen in:
Acta agriculturae Scandinavica. Section A, Animal science
Paginering:
Jaargang 49 (1999) nr. 4 pagina's 251-260
Jaar:
1999-11-25
Inhoud:
Discriminant analysis was used to identify combinations of variables, characterizing patterns of jaw movement (JM) during eating and rumination, that minimize errors when classifying series of successive JM of known behaviour into rumination and eating. JM data from a non-lactating jersey cow were recorded continuously for 72 h. The cow was fed 1800 g of barley straw and 1375 g of dried sugarbeet pulp pellets twice daily. Average times spent eating and ruminating daily were 294 and 462 min. Successive rumination and eating JM were grouped into series when pauses between JM were equal to or longer than a fixed time interval corresponding to the minimum time interval between successive rumination cycles. Time intervals between successive JM, amplitude (the magnitude of the jaw's movement) and number of chews per series of successive JM were calculated for all rumination and eating series and included in the discriminant analyses. The combination of the four variables, basic chewing rate (BCR), mean of amplitude/standard deviation of amplitude, ln(number of chews) and standard deviation of time intervals between successive jaw movements, gave the least minutes of misclassified chewing behaviour per day (3% of total daily chewing time) and yielded a quadratic discriminant function. The order of the variables mentioned rank the variables according to their ability to classify the series. Combinations of the variables BCR and ln(number of chews), and other variables based on mean and standard deviation of time intervals between successive JM and amplitude of JM, can be used with advantage for classifying series of successive JM into rumination and eating behaviour.