Metabolic changes during the transition from the fed to the acute feed-deprived state in prepuberal and mature gilts.
The present study compared the metabolic response to acute feed deprivation in ovariectomized prepuberal (P; n = 6), 62 +/- 2 kg BW, and mature (M; n = 6) gilts, 124 +/- 4 kg BW. Blood was collected at 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, 28, 32, 40, and 48 h after initiation of feeding. Samples were quantified for glucose, insulin, free fatty acids (FFA), beta-hydroxybutyrate (HBA), IGF-I, IGF binding proteins (BP)-1 to -4, cortisol, and amino acids (AA). At 24 h, blood samples were collected every 15 min for 8 h and an additional 1 h after i.v. injection of GnRH (.2 microgram/kg BW) and growth hormone-releasing factor (GRF; 1 microgram/kg BW). Samples were assayed for growth hormone (GH) and LH. Serum insulin concentrations were lower (P < .05) in P gilts. Plasma glucose concentrations were similar. Serum FFA concentrations were greater (P < .05) in P gilts. Serum concentrations of HBA were greater (P < .001) in P gilts at 48 h. Serum IGF-I concentrations were lower (P < .05) in P gilts by 16 h. Serum IGFBP-1-4 levels were similar. Serum cortisol concentrations were similar. Serum concentrations of the essential AA, isoleucine, lysine, threonine, valine, and phenylalanine were greater (P < .05) in P gilts at 40 h. Serum LH concentrations and response to GnRH were similar. Basal serum GH concentrations and peak response to GRF were greater (P < .05) in P than in M gilts. The transition from fed to unfed state occurs more rapidly in P than in M gilts.
Barb
C R
CR
ARS, USDA, Athens, GA 30613, USA.
Kraeling
R R
RR
Rampacek
G B
GB
Dove
C R
CR
D020155:3-Hydroxybutyric Acid; D000375:Aging / Q000378:metabolism* / Q000502:physiology*; D000601:Amino Acids, Essential / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004435:Eating / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D013006:Growth Hormone / Q000097:blood; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006854:Hydrocortisone / Q000097:blood; D006885:Hydroxybutyrates / Q000097:blood; D007328:Insulin / Q000097:blood; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood; D010052:Ovariectomy / Q000379:methods / Q000662:veterinary; D012098:Reproduction / Q000502:physiology; D013552:Swine / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology*
D000601:Amino Acids, Essential; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D007328:Insulin; D018969:Insulin-Like Growth Factor Binding Proteins; D007987:Gonadotropin-Releasing Hormone; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D020155:3-Hydroxybutyric Acid; D006854:Hydrocortisone