title: In ovo administration of recombinant human insulin-like growth factor-I alters postnatal growth and development of the broiler chicken.
abstract: Two experiments assessed the efficacy of in ovo administration of insulin-like growth factor-I (IGF-I) to enhance skeletal muscle development and improve feed efficiency of broilers. Hatching eggs were divided into three groups: uninjected control, vehicle-injected control, and recombinant human (rh) IGF-I (100 ng per embryo). Eggs in Experiment 1 were injected on Day 1, 4, or one of Day 7 through 18 of incubation. Growth rates for Days 1 and 4 resulted in the greatest response to treatment (P < 0.01, P < 0.06 respectively). Based on these results, Experiment 2 focused on Days 1 to 4 of incubation. Results from Experiment 2 showed that there was no significant difference in hatchability among control and rh IGF-I treatment groups. Injection on Day 3 resulted in the greatest response for increased live (P < 0.035) and leg (P < 0.02) weights in both sexes. Feed efficiencies of all rh IGF-I groups were significantly (P < 0.01) improved for the first 3 wk. In ovo administration of rh IGF-I on Day 3 increased feed efficiency (6.65%; P < 0.009) in pens of mixed-sex broilers. In addition, live weights (12.3%; P < 0.002), leg weights (11.7%; P < 0.01), breast weights (9.9%; P < 0.04), and heart weights (11.4%; P < 0.02) were increased in males. These results demonstrate that in ovo administration of rh IGF-I alters feed efficiency, growth, and tissue development. This finding lends itself to significant improvements in broiler production efficiency and profitability.
authors.affiliation: Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26506-6108, USA.
authors.forename: H
authors.initials: H
authors.lastname: Kocamis
authors.forename: D C
authors.initials: DC
authors.lastname: Kirkpatrick-Keller
authors.forename: H
authors.initials: H
authors.lastname: Klandorf
authors.forename: J
authors.initials: J
authors.lastname: Killefer
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000254:growth & development*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development; D011994:Recombinant Proteins
chemical_list: D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I