Concentrations of hormones and metabolites, estimates of metabolism, performance, and reproductive performance of sows actively immunized against growth hormone-releasing factor.
Cyclic females actively immunized against growth hormone-releasing factor (GRF; n = 5) or human serum albumin (HSAi; n = 4) were used to determine the effects of reduced serum somatotropin (ST) and IGF-I on metabolism and production in gestating and lactating sows. Sows farrowed, pigs were weaned at 28 d of lactation, and sows were observed for estrus after weaning. Blood samples were collected at 15-min intervals for 5 to 6 h on d 110 of gestation and d 21 of lactation. Mean ST (nanograms/milliliter) was less (P < .05) in GRFi than in HSAi sows at d 21 of lactation, but it was similar at d 110 of gestation. Serum concentrations of IGF-I were less (P < .05) in GRFi than in HSAi sows at d 21 of lactation but not at d 110 of gestation. Serum thyroxine was greater (P < .05) in GRFi than in HSAi sows during gestation and lactation. Sows actively immunized against GRF weighed less (P < .01) and had more backfat (P < .01) at d 110 of gestation than HSAi sows; in vitro glucose oxidation and lipogenic rate of adipose tissue were greater (P < .05 for treatment x day interaction) in GRFi than in HSAi sows at d 110 of gestation. Across treatment, mammary gland oxidation of glucose and glucose clearance rates increased (P < .05), whereas adipose tissue utilization of glucose decreased (P < .05) during lactation. During lactation, GRFi sows mobilized more (P < .05) backfat than did controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Armstrong
J D
JD
Department of Animal Science, North Carolina State University, Raleigh 27695-7621.
Coffey
M T
MT
Esbenshade
K L
KL
Campbell
R M
RM
Heimer
E P
EP
D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development; D000906:Antibodies / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D005314:Embryonic and Fetal Development / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D013007:Growth Hormone-Releasing Hormone / Q000276:immunology*; D007114:Immunization / Q000662:veterinary; D007117:Immunization, Secondary / Q000662:veterinary; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007774:Lactation / Q000097:blood; D008321:Mammary Glands, Animal / Q000378:metabolism; D011247:Pregnancy; D012098:Reproduction; D012709:Serum Albumin / Q000276:immunology; D013552:Swine / Q000097:blood / Q000378:metabolism* / Q000502:physiology; D013974:Thyroxine / Q000097:blood
D000906:Antibodies; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D012709:Serum Albumin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D013974:Thyroxine