novel approaches to expression and detection of oestrus in dairy cows

another cow, attempting to mount other cows and other sexual activities,
with pedometer readings (Van Vliet and Van Eerdenburg, 1996). Hence
UWB should be beneficial for the more precise timing of AI and could
potentially improve conception rates.
In the modern herd there is limited use for non-automated methods of
detection. Progesterone monitoring is accurate, although not precise at
detecting oestrus, and does not relate to exact time of ovulation. Activity
monitoring is efficient at detecting oestrus, but is coupled with a large error
rate, and although providing an estimated window of time for AI, results in
low conception rates because of the lack of relationship between activity
increase and timing of ovulation. This could perhaps be related to activity
only being recorded in 2 hourly intervals and because activity monitoring is
retrospective reporting oestrus only at milking therefore could be reported
12 hours post onset of oestrus. Unlike UWB which records position twice
per second, in real-time, alerting staff to perform visual observations and
take action as oestrus happens. Hence UWB has the advantage of being
efficient and yet accurate by detecting standing heat, the true indicator of
oestrus (Orihuela, 2000). This method can also detect mounting, as well as
standing to be mounted, which are the signs of oestrus most closely
related to time of ovulation, in order to maximise conception rates (Roelofs
et al., 2005).
5.4.4 Limitations of UWB
Weaknesses of UWB are mainly because it is still in the early stages of
development as a prototype system, and because of its prior application
(monitoring emergency personnel for example in burning buildings/ forest
fires or during natural disasters (Ingram et al., 2004;Ingram, 2006;Harmer
et al., 2008;Dona et al., 2009) as it has not been developed for the
purpose of monitoring cows. The impractically of the UWB unit size and
battery power were major limitations for the purpose of oestrous detection.
Having to mount units in backpacks is not ideal and changing batteries at
least once every 24 hours is inefficient, requiring excessive labour.
However, there is potential to develop the UWB product further, decreasing
the size so that it can be worn on the cow’s neck collar, like activity
monitors. Furthermore, UWB can be run on lower battery power by
removing unnecessary functions included in the prototype and installing an
internal battery to last for a prolonged period of time, if not the productive
life of the cow. The UWB units must also be robust to avoid breakages of
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