Animals can not synthesize the pigment itself. The study also found that only oxygen-containing functional groups (such as hydroxyl, acyl, keto, etc.) of carotenoids (carotenoids) class in livestock, poultry, aquatic products only within the coloring effect. Coloring pigment in plastics testing methods (1) test equipment two roll mill roller presses turn: 25 rev / min, the speed ratio of 1: 1.2 chrome roller surface. Tablet press can be heated and cooled. Two stainless steel mirror panels, inner frame: square-frame, slice thickness 0.5mm. (2) Testing of fertilizer raw materials from PVC resin coloring agents, plasticizers, stabilizers, titanium dioxide Weifang Fuyuan colorants, pigment. (3) Test Method The roller surface temperature was controlled at 160 ℃ colorant, PVC sheet thickness 0.4mm; plastic refining time: 7-8 mins sheet; tabletting: at a temperature of 165 ℃ ~ 170 ℃ tabletting time 1 minute packing speed cold. (4) the colorimetric measurement standard color value to calculate the K / S value fertilizer additive, color strength test and it may be the difference between two standard samples of Comparative coloring power, when adjusted to either have the same coloring power. Testing may also be high density polyethylene, low density polyethylene, and polypropylene. Weifang Fuyuan colorants, Weifang Fuyuan (certified), colorants provided by Environmental Science and Technology Co., Ltd. Weifang Fuyuan. Weifang Fuyuan Environmental Protection Technology Co., Ltd. (www.wfdafuyuan.com) Shandong Weifang, the other leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Weifang Fuyuan leadership with the staff warmly welcome all inquiries negotiations to create Weifang Fuyuan a better future.