title: Physiological and immunological responses to weaning and transport in the young pig: modulation by administration of porcine somatotropin.
abstract: To examine the effects of exogenous porcine (p) ST on measures of stress and immune function in weaned pigs with or without transport, pigs (20 +/- 1 d of age) received daily injections of pST (0.5 mg/kg; n = 16) or saline (n = 16) for 5 d. On d 5, a blood sample was collected immediately before injection. At 4 h postinjection, pigs were weighed, sampled for blood, injected with di-nitrophenyl-conjugated keyhole limpet hemocyanin, and weaned. One half of the pigs in each group were transported for 3 h before placement in the nursery. Pigs were weighed, and blood was collected on 1, 7, and 14 d postweaning. Statistical significance was set at P < 0.05. Serum IGF-I concentrations were increased by pST and decreased by weaning, but not affected by transport. The free cortisol index was elevated in all pigs 1 d postweaning, although less in transported versus nontransported pigs. By 7 d postweaning, the free cortisol index returned to prewean values. Serum concentrations of immunoglobulin (Ig) G increased in all pigs by 14 d postweaning, but were not affected by pST or transport. Serum IgM concentrations were elevated at 7 and 14 d postweaning. Before weaning and again 1 d postweaning, pigs treated with pST had greater concentrations of IgM than did control animals. Circulating neutrophils increased in pST-treated pigs 4 h after the final pST injection. Improved immune function in weaned pigs by pST may lead to greater health and growth in a commercial setting.
authors.affiliation: Department of Animal Science, University of Tennessee, Knoxville 37996, USA. ckojima@utk.edu
authors.forename: C J
authors.initials: CJ
authors.lastname: Kojima
authors.forename: H G
authors.initials: HG
authors.lastname: Kattesh
authors.forename: M P
authors.initials: MP
authors.lastname: Roberts
authors.forename: T
authors.initials: T
authors.lastname: Sun
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006234:Handling, Psychological; D006854:Hydrocortisone / Q000097:blood; D007107:Immune System / Q000187:drug effects*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects; D008297:Male; D011897:Random Allocation; D013312:Stress, Physiological / Q000187:drug effects*; D013552:Swine / Q000276:immunology / Q000502:physiology*; D014156:Transcortin / Q000378:metabolism; D014186:Transportation; D014886:Weaning
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D014156:Transcortin; D006854:Hydrocortisone