title: Performance and ruminal protozoa in lambs with chromium supplementation.
abstract: The effects of chromium picolinate (CrPic) oral supplementation on the performance and ruminal protozoa population in sheep was investigated. Twenty-four male lambs were treated with four different levels of CrPic: placebo, 0.250, 0.375 and 0.500mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Feed intake was measured three times a week. Lambs were weighed every 2 weeks. Ruminal content was sampled five times during the trial to quantify ruminal protozoa. No difference (p>0.05) between treatments was recorded for any parameter measured: initial and final mean body weight, dry matter intake, daily gain and total body weight gain. There was a negative linear relationship between Cr supplementation and protozoa count (p=0.0013) with no additional decrease when CrPic supplemental levels were higher than 0.375mg/day. Therefore, Cr supplementation must be carried out carefully and more studies need to address stressed animals or possible toxic effects of Cr in the animal itself or to the ruminal protozoa population.
authors.affiliation: Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Distrito Federal 70910-900, Brazil. brunodallago@yahoo.com.br
authors.forename: B S L
authors.initials: BS
authors.lastname: Dallago
authors.forename: C M
authors.initials: CM
authors.lastname: McManus
authors.forename: D F
authors.initials: DF
authors.lastname: Caldeira
authors.forename: A C
authors.initials: AC
authors.lastname: Lopes
authors.forename: T P
authors.initials: TP
authors.lastname: Paim
authors.forename: E
authors.initials: E
authors.lastname: Franco
authors.forename: B O
authors.initials: BO
authors.lastname: Borges
authors.forename: P H F
authors.initials: PH
authors.lastname: Teles
authors.forename: P S
authors.initials: PS
authors.lastname: Correa
authors.forename: H
authors.initials: H
authors.lastname: Louvandini
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D008297:Male; D010848:Picolinic Acids / Q000494:pharmacology*; D012417:Rumen / Q000469:parasitology* / Q000502:physiology*; D012756:Sheep / Q000254:growth & development*
chemical_list: D010848:Picolinic Acids; C030614:picolinic acid