Abstract:

Due to the low utilization rate of copper and zinc, the metabolic system of livestock excretes most of the copper and zinc intake with feces and urine. Applying manure made of this sort of excrement can cause accumulation of copper and zinc in soil, destruct the soil texture and microbes, have negative influence on the yields and nutrients of crops, increase the content of copper and zinc in crops and potentially harm human health through the food chain. China’s livestock and poultry breeding industry has entered a large-scale stage with the largest number of pigs and poultry in the world, and the residue of copper and zinc in livestock and poultry excrement has become one of the most urgent problems in agricultural environment management. In view of current situation, this paper reviewed the research process of promoting the absorption of copper and zinc in livestock and poultry and reducing the bioavailability of them in the feces through the application of different technologies, including applying amino acid chelates of copper and zinc, using passivating agents in composting, adopting biological leaching, electrochemical and organic acid extraction methods. Suggestions on regulating feed production, managing breeding and improving organic fertilizer standards were put forward, which could provide a theoretical and technical basis for solving the problems of copper and zinc pollution in agricultural environment in China.

Key words: livestock and poultry excrement, copper, zinc, pollution, treatment