title: Serum insulin-like growth factor I (IGF-I) concentrations are increased in pigs fed antimicrobials.
abstract: The effect of antimicrobial supplementation on the sera concentrations of IGF-I was determined in crossbred weanling pigs. Pigs were allotted by weight, litter, and sex to either a control diet or a diet supplemented with ASP-250 (22.7 ppm of chlortetracycline, 22.7 ppm of sulfamethazine, and 11.4 ppm of penicillin) for 5 wk. The diets contained 21.8% crude protein and 1.15% lysine. Growth performance data were collected weekly. Insulin-like growth factor I and insulin-like growth factor binding protein (IGFBP) analyses were performed on blood samples that were drawn during the final week of the trial. Feeding ASP-250 to young pigs increased their sera IGF-I concentrations by 24.8% (P < .001). A 59% increase in sera IGFBP-3 levels also was observed. The pigs fed ASP-250 had a 26% increase in average daily gain (P < .01), a 6.7% improvement in gain:feed ratio (P < .05), and a 18.5% increase in feed consumption (P < .01) compared with pigs fed the control diet. Increased serum IGF-I concentrations with antimicrobial feeding may be involved in the enhanced growth performance observed.
authors.affiliation: Department of Animal Science, University of Minnesota, St. Paul 55108, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Hathaway
authors.forename: W R
authors.initials: WR
authors.lastname: Dayton
authors.forename: M E
authors.initials: ME
authors.lastname: White
authors.forename: T L
authors.initials: TL
authors.lastname: Henderson
authors.forename: T B
authors.initials: TB
authors.lastname: Henningson
mesh_terms: D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002751:Chlortetracycline / Q000494:pharmacology; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects / Q000502:physiology; D005260:Female; D005527:Food, Fortified; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D010406:Penicillins / Q000494:pharmacology; D011863:Radioimmunoassay / Q000662:veterinary; D011897:Random Allocation; D013418:Sulfamethazine / Q000494:pharmacology; D013552:Swine / Q000097:blood* / Q000254:growth & development / Q000502:physiology; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D018969:Insulin-Like Growth Factor Binding Proteins; D010406:Penicillins; D013418:Sulfamethazine; D007334:Insulin-Like Growth Factor I; D002751:Chlortetracycline