Use of rare earth elements as feed additives in pig production.
2005
Rambeck, W. A. | Wehr, U.
Growth promoters or performance enhancers are used worldwide in pig production. For over 50 years, the use of antibiotics as feed additives proved to be effective by improving nutrient utilization leading to improved feed conversion ratio and better growth rate in most cases. In the EU, the use of these feed antibiotics is prohibited now, and the remaining few still allowed will be banned at the end of 2005. In China salts of the rare earth elements or lanthanides (lanthanum, cerium among others) have been used as feed additives in animal production for more than forty years. Numerous reports in the Chinese literature indicate that a small amounts of rare earth element mixtures in the diet increase not only the liveweight gain of pigs, cattle, sheep and chickens but also milk and egg production. In the past five years a dozen or so studies, mainly in pigs, have been performed under western production conditions. The results from these indicate that the use of rare earth elements imported from China improves liveweight gain and feed conversion. The mechanism of action of these elements is not well understood. It is thought that they develop their activity in the digestive tract since very little is absorbed. Rare earth elements might be of interest in animal and especially in pig production as a new, safe and inexpensive alternative growth promoter.
显示更多 [+] 显示较少 [-]