|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/1999
Publication Date: N/A
Technical Abstract: When a pregnant sow is stressed, cortisol crosses the placenta to possibly affect the fetus. Because modern production has the potential to stress sows, we examined the physiology of pigs whose dams were injected with ACTH during gestation. Control sows (n=8) were given no treatment while the treatment sows (ACTH, n=8) were administered an i.v. injection of ACTH (1 IU/kg BW) weekly from 6- to 12-wk of gestation. Three male pigs from each sow were sacrificed at either birth, 1- or 2-mo of age for collection of hypothalamic, pituitary and adrenal tissue. Hypothalamic corticotropin releasing factor (CRF) and beta-endorphin (b-endo) as well as mRNA for proopiomelanocortin (POMC) and the adrenal gland ACTH receptor were quantified. At 2.5-mo of age a blood sample was taken from one pig from each litter and then the pig was placed in a pen with unfamiliar pigs for 10 d. Blood samples collected every other day to determine plasma cortisol lconcentrations. At 1-mo of age, ACTH pigs tended (P=.08) to have greater mRNA for the ACTH receptor than CONT pigs (1.27+/.16 vs .82+/.15 relative units) and concentrations of CRF (1.26+/.11 vs .77+/.25 ng/g), but lower b-endo (9.6+/1.5 vs 17.8+/2.5 ng/g; P<.02). There was a treatment by period interaction for mRNA for POMC, with ACTH pigs expressing less than CONT pigs at birth (1.29+/.17 vs 1.88+/.20 relative units; P<.007) and greater concentrations at 2 mo (3.06+/.28 vs 2.27+/.28 relative units; P<.007). ACTH pigs tended to have heavier pituitaries than CONT pigs at 2 mo of age (.007+/.001 vs .005+/.001 g/kg BW; P<.08). In response to mixing, ACTH pigs had greater plasma cortisol than CONT pigs (70.79+/3.79 vs 59.61+/3.83 ng/mL; P=.03). These data indicate that exogenous ACTH during gestation alters the HPA axis of the sow's subsequent offspring.