novel approaches to expression and detection of oestrus in dairy cows

ate decreased dramatically to an average of 53.5%, without any increase
in script accuracy; therefore the optimised script resulted in the best
oestrous detection.
From the daily analysis of the reports of oestrus, mounting and standing
behaviour, it was clear that the incidence of erroneously declared mounting
was more prevalent on days when cows were actually in oestrus (Tables
5.5 and 5.6). It was also clear that more error was attributed to cows that
came into oestrus during the trial compared to control cows not in oestrus.
The increased error during oestrus could be due to the number of cows in
oestrus at once; for example increased number of cows in oestrus
increases oestrous expression (Hurnik et al., 1975;Van Vliet and Van
Eerdenburg, 1996), which may mean that the error is a result of the
experimental design because 6 cows were synchronised to come into
oestrus simultaneously. In a commercial situation the number of cows in
oestrus together may be lower which could result in a more accurate
detection rate.
Spikes in the data affect the accuracy of mounting detection because in the
UWB data error spikes are recorded in the same format as actual mounts
and so could be mistaken. Falsely declared mounts were investigated by
looking at the MU position on CCTV cameras. This showed that there was
no pattern associated with the error spikes. Potential reasons could be
attributed to a cows’ position in an area of poor geometry in the dairy barn
(Figure 4.9), or due to non-line of sight from the master unit (Harmer et
al., 2008). Because the dairy farm is a complex environment with various
obstructions, line of sight may become obstructed and thus cause
reflections in the signal which give false or less accurate 3D positions.
Although, filtering by script analysis can help to eliminate these spikes.
Upon further analysis of the data from POC 2 and POC 3 it appears that
data quality in POC 2 was better than POC 3, therefore data from POC 3
required further filtering. It is obvious that 2 MUs in POC 3 had higher
incidence of error and more false positives were declared by script analysis
(Cow 38 and 623; control cow and oestrus cow). These particular MUs
were tested against a normally functioning MU in the same BU network in
the same positions of good geometry; results revealed no difference in
position or error, leading to the conclusion that error could be attributed to
a cow’s favoured position within the location, which could be an area of
poorer geometry and more obstruction. Furthermore it is possible that
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