title: Weaning pig performance and faecal microbiota with and without in-feed addition of rare earth elements.
abstract: Two 6-week feeding trials were conducted on a total of 112 newly weaned piglets to examine the recently reported growth promoting effects of dietary rare earth elements (REE) in European pig production. Rare earth element-diets were supplemented with a REE-citrate premix of lanthanum and the light lanthanoides cerium, praseodymium and neodymium at 200 mg/kg for 6 weeks after weaning. Overall for both trials, growth performance of REE-citrate and control fed piglets did not differ significantly (p > 0.05). An early enhancive tendency for REE-citrate in trial 1 (feed conversion ratio, FCR -3%, p = 0.15) proved irreproducible in trial 2. In the late period of trial 1, in-feed addition of REE-citrate significantly impaired piglet performance (FCR + 8%, p = 0.01). A cultivation-independent molecular approach, polymerase chain reaction-denaturing gradient gel electrophoresis was further applied to assess REE induced alterations in the predominant faecal microbiota from weaning pigs. Calculation of various ecological characteristics does not indicate (p > 0.05) an often discussed selective effect on local microbial composition of dietary REE.
authors.affiliation: Institute of Animal Nutrition, Faculty of Veterinary Medicine, Free University Berlin, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kraatz
authors.forename: D
authors.initials: D
authors.lastname: Taras
authors.forename: K
authors.initials: K
authors.lastname: Männer
authors.forename: O
authors.initials: O
authors.lastname: Simon
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002563:Cerium / Q000008:administration & dosage / Q000494:pharmacology; D019343:Citric Acid / Q000008:administration & dosage / Q000494:pharmacology; D005243:Feces / Q000382:microbiology*; D005260:Female; D007811:Lanthanum / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008674:Metals, Rare Earth / Q000008:administration & dosage / Q000494:pharmacology*; D009354:Neodymium / Q000008:administration & dosage / Q000494:pharmacology; D011221:Praseodymium / Q000008:administration & dosage / Q000494:pharmacology; D011897:Random Allocation; D013552:Swine / Q000254:growth & development*; D014886:Weaning
chemical_list: D008674:Metals, Rare Earth; D019343:Citric Acid; D009354:Neodymium; D002563:Cerium; D007811:Lanthanum; D011221:Praseodymium