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International audience; Long-term monitoring of animal activity can yield key information for both researchers in ethology and engineers in charge of developing precision livestock farming tools. First, a barn is segmented into delimited areas (e.g. cubicles) with which an activity can be associated (e.g. resting), then a real-time location system (RTLS) can be used to automatically convert cow position into behaviour. Working within the EU-PLF project, we tested a system already able to determine basic activities (resting, moving, eating…) and logged a “big data” set of billions of data points (123 days 190 cows 1 location-per-second readings). We then focused on integrating image analysis techniques to help visualise and analyse the dataset, first to validate the data and then to enrich the information extracted. The algorithm developed using freely available tools quickly confirmed the ability of the system to determine cows' main activities (except drinking behaviour), even with 11% of positions missing. The good localisation precision (16 cm) made it possible to enrich the time-budget with new activities such as using brushes and licking mineral blocks. For both activities, using visual observations as gold standard, activity profiles with excellent sensitivity (nearly 80%) were extracted. This validation procedure is both necessary and generalisable to other situations. The improvement of biological information contained in such data holds promise for people designing alarm devices and health and welfare indicators for farmers and/or vets.

This study assessed the extent to which eating solid foods and social contacts influence nibbling objects and improve the welfare of veal calves. Animals were fed milk replacer only vs. supplemented with solid foods and were housed in individual stalls vs. together in pens. Time budget, reactions to handling in a weighing machine, growth, health (length of medical treatments) and abomasal lesions were assessed. In addition, chronic activation of the hypothalamo–pituitary–adrenocortical axis was evaluated after ACTH and CRF challenges, and that of the sympathetic nervous system, through activities of catecholamine-synthesising enzymes. The provision of solid foods reduced time spent nibbling objects and being inactive in proportion to and at the time of the increase in time spent eating and chewing. The calves housed together in pens had higher basal cortisol levels and they reacted to weighing. Health and physiological indices of chronic stress did not vary with feeding or housing conditions. It is concluded that nibbling in veal calves derives at least in part from a lack of development of feeding behaviour appropriate to ruminants. There was no clear evidence of poorer welfare due to feeding on milk replacer only or individual housing, but calves reared in groups seemed more stressed by handling than calves reared in individual stalls.

The reprocessing-conditioning-recycling (RCR) strategy experimented by COGEMA drastically reduces the volume and the radiotoxicity of ultimate residues to be disposed. Technical improvements at the La Hague reprocessing plant, including compaction of hulls and end-fittings, decreases the volume of long-lived residues to less than 0.5 m3 per t HM (heavy metal), far less than 2 m3 yielded for direct disposal of spent fuel. Moreover, a Universal Canister of same shape and dimensions as a glass canister for vitrified fission products has been designed to standardize these residues. Respectively, the new management of short-lived technological wastes will lessen their volume from 1.4 m3 per t HM in 1995 down to around 0.6 m3 by 2000.