Careful monitoring of cows helps to minimize pain and distress during calving, and knowledge
of the time of birth is important to ensure timely and adequate uptake of colostrum.. However,
direct visual observation is time consuming and continuous presence of an observer during
stage two of calving can disturb cows; therefore, to predict precisely the calving time, various
methods have been proposed to automatically and remotely measure physiological (body
temperature; blood level of oestrone- sulphate, 17 beta oestradiol and progesterone; electrolytes
in mammary secretion), physical (relaxion of pelvic ligaments; physical separation of the vulva
lips) and behavioural indicators. Restlessness is one key behavioural change occurring when
calving is approaching. Video cameras or accelerometers recording behaviour of cows can
be integrated in systems using image analysis or locomotive activity to alert the farmer when
calving is approaching; however, alerting systems require input of benchmark information
about behaviours and changes in behaviours which can be predictive of the time of calving.
Eight cows in a calving barn were continuously video-monitored. The recordings of the 24 h
before calving were analysed to identify the routine behaviours associated with an imminent
birth. In our conditions, the only behaviour that was significantly influenced by the distance
from calving was frequency of lying bouts; the average number of lying bouts started to increase
(P<0.0001) at 3 h before calving reaching the greatest (P<0.0001) value during the last two
hours before calving. Increase in the frequency of lying bouts may be an indicator of restlessness
useful to predict approaching calving, but further studies are needed to input benchmark values
in automated alerting systems
