title: Effect of feed intake on antimicrobially induced increases in porcine serum insulin-like growth factor I.
abstract: This study was conducted to determine whether an antimicrobially induced (ASP-250) increase in serum IGF-I was the result of differences in feed intake. Serum IGF-I concentrations were measured in crossbred pigs that were fed a control diet or a diet supplemented with ASP-250 either for ad libitum consumption or limited to 85% of the control pigs' consumption. The pigs that consumed either diet ad libitum, control or ASP-250, consumed similar quantities of feed. The ASP-250 ad libitum-intake pigs had serum IGF-I concentrations that were greater (P<.01) than those of their ad libitum-intake control littermates. Similarly, the ASP-250 limit-fed pigs had serum IGF-I concentrations that were greater (P<.01) than those of the controls. Although the serum IGF-I concentrations of pigs fed the ASP-250-supplemented diet for ad libitum intake were greater than the serum IGF-I concentrations of the pigs limit-fed the ASP-250-supplemented diet, the differences were not significant (P<.08). The ASP-250-fed pigs had higher serum IGF binding protein (BP)-3 concentrations than did their control littermates (P<.003). A time course of antimicrobially induced alterations in serum IGF-I concentrations revealed that the effect of increased serum IGF-I levels in ASP-250-supplemented pigs (P<.02) was observed within 4 d and was maintained throughout the 4-wk study. These findings show that feed intake is not responsible for the increase in serum IGF-I observed with ASP-250 supplementation. Additionally, the antimicrobially induced increase in serum IGF-I concentrations occurs within a few days after initiation of the treatment.
authors.affiliation: Department of Animal Science, University of Minnesota, St. Paul 55108, USA. hathaway@tc.umn.edu
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: D A
authors.initials: DA
authors.lastname: Young
authors.forename: T N
authors.initials: TN
authors.lastname: Doan
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002751:Chlortetracycline / Q000494:pharmacology*; D004338:Drug Combinations; D002149:Energy Intake; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008024:Ligands; D010400:Penicillin G / Q000494:pharmacology*; D011817:Rabbits; D013418:Sulfamethazine / Q000494:pharmacology*; D013552:Swine / Q000097:blood*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D004338:Drug Combinations; D018969:Insulin-Like Growth Factor Binding Proteins; D008024:Ligands; D013418:Sulfamethazine; C054065:chlorotetracycline, penicillin G, sulfamethazine drug combination; D007334:Insulin-Like Growth Factor I; D010400:Penicillin G; D002751:Chlortetracycline