novel approaches to expression and detection of oestrus in dairy cows

and ruminating and, as results from preliminary trials show (see Chapter
4), mounting behaviour was not inhibited.
5.2.3 Experimental Design
Figure 5.1 describes the general experimental design of the proof of
concept trials. On day 0 six cows were synchronised with CIDRs. Milk
sampling and activity monitoring also commenced on day 0, throughout
UWB recording and continuing until 5 days after, to ensure collection of
data before, during and after oestrus. On the morning of day 6 UWB
recording began and the 6 cows to be synchronised were injected with
Estrumate. On day 7 CIDRs were removed, and then during days 8, 9 and
10 cows displayed oestrus. UWB recording ended on the morning of day 13
(for POC 2 and 3; ended prematurely at day 11 for POC 1) after recording
UWB data for 24 hours for 7 days. Visual observation and CCTV recording
occurred simultaneously with UWB data collection (Figure 5.1).
CIDR
insertion
Estrumate
i.m.
injection
CIDR
removal
Figure 5.1 A diagram to show the experimental design of proof of concept trials per day. Cows
were synchronised with CIDRs at day 0. Milk sampling and activity data collection also began at
day 0 through to the end of the trials at day 17. Estrumate injection was administered
intramuscularly at day 6, with UWB recording also beginning in the morning of day 6. On day 7
CIDRs were removed which allowed for oestrus to take place on the following days. UWB
recording ended on the morning of day 13 recording continuously for 24 hours over 7 days (in
POC 2 and 3). UWB recording during POC 1 ended prematurely on day 11.
5.2.4 Synchronisation
Six cows were selected for synchronisation and approved for use on trial by
the Named Veterinary Surgeon. On day 0 one Eazi-Breed CIDR device
(InterAg, Hamilton, New Zealand; Cockburn Veterinary Group, Leics, UK)
was inserted per vagina of each cow. The CIDR (controlled internal drug
releasing) device is an intra-vaginal pessary containing 1.38g progesterone
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