Increased drainage area in fully-slatted floors with rubber mats for growing and finishing bulls

Hygiene in animal housing is of highest importance for both animal welfare and food safety. In new built cattle barns with pens of fully slatted flooring, it is since 2007 a legal requirement that the surface is made of rubber or other soft material. Fully slatted floors with rubber mats have shown to improve animal welfare and claw and leg health when compared with concrete slatted floors. However, the previous maximum allowed slot (gap) opening has been reduced from 35 and 40 mm to now 30 and 35 mm (depending on the animal's weight) regardless of if slat surface is concrete or rubber.  As the total opening area decreases when adding a rubber mat on the concrete, this becomes a hygienic problem in many herds because the drainage of manure is fundamental for obtaining an acceptable hygiene on floors with fully slatted flooring.

The aim of the study is to see if an increased slot opening and reduced the slat width of the slatted rubber flooring can improve drainage capacity and improve floor and animal hygiene and still  maintaining good animal welfare and without affecting the risk of traumatic injuries. The study is being conducted in a newly built barn where half of the boxers have 5 mm wider slots and the other half maintain the original legislated openings. Thus the total drainage area increased from 14% to 18% (maximum allowance is 28%). The bulls are videos filmed to assess behavior, rising and lying down. At regular farm visits locomotion, body condition, leg lesions, hygiene of animals and floors are recorded. After slaughter claw growth and claw disorders are assessed and recorded. The results will be presented 2018.