Mechanical dung-removal systems (manure scrapers) are standard equipment in dairy-cattle cubicle housing. Regular removal of faeces and urine several times daily is very important for claw health. Since the manure scrapers are mobile fittings in the cows’ walking area, the animals cannot help but come into contact with them. This contact may be associated with behavioural problems in the form of involuntary displacement of the animals, or health problems in the form of injuries to the claw/limb area. Certain aspects of this equipment which are problematic in terms of the hazard posed to humans are covered by the provisions of the Federal Law relating to the Safety of Technical Equipment and Appliances (STEG) and the relevant federal ordinance (STEV). Together with a working group comprising experts from the industry and research sectors, the Advisory Bureau for Accident Prevention in Agriculture (BUL) has compiled safety standards which also address the risk of injury to animals. Manure scrapers are not evaluated within the framework of the testing and authorisation procedure for mass-produced housing systems and equipment. Since, however, they have been in use for some time now in cattle husbandry – though not in pig husbandry – certain aspects concerning the design and operation of manure scrapers are very well known. In terms of a comprehensive assessment of manure scrapers from an animal-welfare perspective, however, some important questions remain unanswered. The aim of the present project is to acquire sound knowledge on the effects of manure scrapers on different aspects of behaviour and on injuries to the lower limbs. It is hoped that the findings will serve as a basis for the improved information of animal-housing construction firms, livestock producers and persons in charge of enforcing legal regulations. To this end, and initially with the aid of direct observations and heart-rate measurements, contacts between the animals and the manure scraper are to be assessed in terms of their effect on the animal and classified as either stressful/harmful or non-stressful/non-harmful. Subsequently, in the main trial, four different types of scrapers will be studied with respect to various behavioural aspects on 5 – 10 commercial farms in each case. It is anticipated that 10 scraping passes will be taken into account per farm. Immediately after the observation period, cows that have undergone contact with a scraper deemed to be ‘stressful’ will be taken into the claw stand where their claws and the lower parts of their legs will be washed and examined for fresh injuries. In addition, a questionnaire is to be used to determine whether infectious claw diseases occur more frequently with specific types of scrapers, or whether there is a correlation between such diseases and the length of the interval between cleanings.
