novel approaches to expression and detection of oestrus in dairy cows

meant that for future trials the maximum number of cows could only be
12; 12 MU and 8 BU, sampling at 2Hz, relaying precise position at twice
per second.
4.3.3.3 24 Hour Trial
The purpose of the 24 hour trial was to ensure natural behaviour occurred
in all cows whilst wearing the backpacks, and to test whether recording by
UWB could continue for a longer period of time. Initially 15 cows were
involved in a 24 hour trial, although due to units ‘dropping out’ (because of
the maximum UWB unit number as discussed above); the positioning data
of only 12 cows was recorded over 24 hours. Importantly monitoring of the
12 cows for 24 hours continued without problem, except for battery power
failing and the need to change batteries to ensure the MUs continued to
communicate position in order to obtain, as much data as possible. Data
from this trial confirmed that UWB position of 12 cows can be recorded
continuously, and that all cows display natural behaviour when wearing the
backpacks.
Data from the 24 hour trial was also analysed via an automated script, and
results compared against CCTV records (as detailed in section 4.3.3.1).
During this trial no cow showed oestrus. However, 4 incidences of false
mounting were reported upon script analysis, involving only 6 cows;
therefore maximum number of 2 mounts occurred, according to the script,
per cow. This data was therefore not indicative of oestrus due to the
insignificant number of mounts occurring in a 24 period, and mounts were
confirmed as false positives by post-trial CCTV analysis.
In summary, 12 cows can be monitored accurately using UWB, even in
positions where signal quality may be poor. UWB is capable of recording
precise cow movements and importantly oestrous behaviour, recording
changes in height and the positional relationship between 2 cows engaging
in this activity.
4.4 CONCLUSION
The aim of this work was to develop UWB as a novel technology with the
potential to monitor oestrous detection in dairy cows. Particular challenges
were the environment of the dairy which could affect accuracy of position.
Optimising BU positioning led to precise positioning in 3 dimensions, 2 to
3cm accuracy in horizontal axes and approximate 10cm accuracy in vertical
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