title: [The effectiveness of rare earth elements as a possible alternative growth promoter for pigs and poultry].
abstract: Mixtures of Rare Earth Elements (REE) have been used as animal growth-promoters on a large scale in China during the last 20 years. Numerous studies carried out in China claim it produces quite sensational growth-promoting effects in all categories of farm animals. To explore the question of whether REE's might prove suitable as a growth-promoter under western keeping conditions, feeding experiments were performed on pigs and poultry. The animals received a typical diet, supplemented with REE salts in concentrations between 75 and 300 mg/kg feed. Weight-gain, feed-intake, feed-conversion and (where applicable) laying parameters were observed. It was shown that in pigs receiving feed supplemented with REEs, an increase in daily weight gain of up to 19% and an improvement in feed-conversion of up to 11% can be achieved, whereas, for poultry, no positive effects on growth or productivity of the animals could be observed. Testing of important organs via Neutron Activating Analysis (NAA) showed a minute accumulation of REE, principally in liver and bones. Analysis of the poultry gut-flora, using selective media, showed that the main microorganism populations of the alimentary canal were unaffected by feed-supplementation with REE.
authors.affiliation: Institut für Physiologie, Physiologische Chemie und Tierernährung, Lehrstuhl für Tierernährung und Diätetik, Ludwig-Maximilians-Universität München.
authors.forename: S
authors.initials: S
authors.lastname: Schuller
authors.forename: C
authors.initials: C
authors.lastname: Borger
authors.forename: M L
authors.initials: ML
authors.lastname: He
authors.forename: R
authors.initials: R
authors.lastname: Henkelmann
authors.forename: A
authors.initials: A
authors.lastname: Jadamus
authors.forename: O
authors.initials: O
authors.lastname: Simon
authors.forename: W A
authors.initials: WA
authors.lastname: Rambeck
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000254:growth & development*; D003370:Coturnix / Q000254:growth & development*; D002149:Energy Intake / Q000187:drug effects; D005260:Female; D006133:Growth Substances / Q000494:pharmacology*; D008297:Male; D008674:Metals, Rare Earth / Q000494:pharmacology*; D010058:Oviposition / Q000187:drug effects; D013552:Swine / Q000254:growth & development*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D006133:Growth Substances; D008674:Metals, Rare Earth