Disclosed herein are methods of treating an edible fiber source to make an animal feed with increased digestible energy. A precast board is manufactured by embedding a pile head fitting tubular body which is constituted by a side plate forming a pile head fitting tubular body and a closing plate closing open one end of a tube body, and forms an opening portion in another end open so as to freely fit a pile head. 1 atm % or less and an Sn of 3 atm % or less. The size of the image is controlled by change of the amplitude of the light scanning device while the amplitude is changed along with the driving energy. Further, a multi-microcolumn using the method is provided. Here, the single region and the overlapping region are switched when one medium is printed.