Corn and soybean meal are the main sources of energy and protein for the feed. The quality of the corn and soybean meal varies from region to region, and the energy and protein provided are also different. Then manufacturers will have differences in the procurement of raw materials. Relatively speaking, large-scale enterprises have high quality requirements and quality guarantees because of the perfect testing equipment. The quality of some small feed mills is relatively unstable. This will result in different growth rates of the flock and a different ratio of meat to meat.