Floorboards comprising a core and a surface layer with curved edge portions, which are formed by a compression of the core. The firing assembly also has a finger-pull mechanism. The piston block is glidingly movable in the horizontal direction in the first tube. The end face of the charge air cooler is arranged relative to the cross-section of the pipe conduit at an angle of >45\xb0. In the wavelength path sending or receiving by the wavelength path multiplexingdemultiplexing optical transmission apparatus, a non-selectable combination between a wavelength and a route can be avoided. Therefore, the propionibacteria of the invention made the cows more energy efficient as cows produced the same amount of milk, yet consumed less dry matter.