For iodide radio labelling of chicken PRL, a modified chloramine T method which reduced the amount of chloramine T and omitted sodium metabisufite,and produced the labeled hormone with a specific activity of 29μCi/μg was used.
The determination of feed grade potassium iodide content with the method of potassium iodate and the method of iodine-starch indicator was discussed in comparism with the method of the national standard GB8256-87,it showed that the two methods are simple,accurate,reproducible and easy mastered and the discolouration of destination is sharp.
When supplement of zinc, selium or iodine was as twice ascontrol (zinc, 50mg/kg; selium, 0. 1mg/kg; iodine, 0.3mg/kg) respectively, the yolkcolor was i~p to 8 degree or above, which conform to international regulation of egg ex-port or import.
4.The digestion of nutrients was the highest (P<0.05), when adding 10mg/kg F and 50-75mg/kg I, and F deposotion in bone (P<0.05) and kidney (P<0.05), of the group adding 100mg/kg F was the highest by slaughter. However ,the sheep did not appeared toxic phenonmena ,also daily growth was significant.