Year: 2011
Type: dissertation
Abstract: The aim of this project was to quantify the total sleep time in modern dairy cows during\n24-hour periods and to investigate whether the total amount of sleep as well as time\nspent in different sleep stages varies between the dry period, early- and peak lactation.\nThe distribution of sleep time between night and day was also examined. Furthermore,\ncorrelations between sleep and lying time, fluctuations in body temperature and heart\nbeat were included in the aim. Eight dairy cows of the Swedish Red breed were used in\nthis study, which was carried out between June and September 2010. In order to\nquantify sleep non-invasive electrophysiological recordings were performed.\nSimultaneously with collecting sleep data, body position and body temperature were\nalso recorded. No heart rate data was obtained due to difficulties of maintaining\nelectrodes for heart beat measurements attached to the skin. One 24-hour data\ncollection was performed on each cow in the three different stages of lactation. The\nelectrophysiological data was visually scored according to definitions of human sleep.\nElectrophysiological data from one of the eight cows mainly contained artefacts and all\nher data was excluded from the data set. Shorter sleep time was obtained in early- and\npeak lactation compared with the dry period. The rapid eye movement (REM) sleep time\nand REM sleep time in proportion of total sleep was higher in peak lactation compared\nto early lactation. It could also be concluded that cows sleep during larger proportion of\nthe night compared with the day. Indications of a possible correlation between total\nsleep time and total lying time was found, but no relationship between sleep and\nfluctuations in body temperature. Possible correlations between sleep and heart beat\ncould not be investigated since no heart rate measurements was not obtained.
Author: Emma Nilsson
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W16223902