- Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences
Ternman, Emma; Hänninen, Laura; Pastell, Matti; Agenäs, Sigrid; Nielsen, Per Peetz
Sufficient sleep time is important for both an adequate metabolic system and the immune function. Sleep in animals is often estimated by behavioural observations, or recorded on restrained animals with invasive electroencephalogram (EEG) techniques, which might affect sleep patterns. Earlier studies on sleep in cows showed that they sleep about 4 h per day and drowse almost twice the time. The aim of this study was to record and differentiate between vigilance states in dairy cows using a non-invasive EEG method.
Brain activity (electroencephalography, EEG), eye movements (electrooculography, EOG) and muscle activity (electromyography, EMG) were recorded for 6 h per animal using surface-attached electrodes to measure different vigilance states. Behaviour registrations from direct observations were combined with the EEG data in order to confirm the identification of different vigilance states from the EEG, EOG and EMG recordings. 8 dry dairy cows, lactation number 1-8 and age 3-11 years, of the Swedish Red breed from the research herd at Kungsängen Research Centre, Uppsala, Sweden, were used in the study.
The EEG recordings showed that non-rapid eye movement (NREM) sleep displayed low frequency waves, sometimes with slow wave activity. Rapid eye movement (REM) sleep and alert wakefulness shared similar features of desynchronised waves with varying frequency and could be differentiated by reduced neck muscle activity during REM sleep.
The main conclusion from this study is that it is possible to distinguish different vigilance states in dairy cows using surface-attached EEG electrodes.
Dairy cows; Sleep stages; Drowsing; NREM; REM
Applied Animal Behaviour Science
2012, Volume: 140, number: 1-2, pages: 25-32
Publisher: ELSEVIER SCIENCE BV