|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2000
Publication Date: N/A
Technical Abstract: Chronically stressed swine may experience adverse effects on development, immune function and behavior. When a pregnant sow is stressed, cortisol (CS) crosses the placenta to possibly affect the fetus, a process termed prenatal stress. This study examined the physiology and behavior of pigs whose dams were injected with ACTH during pregnancy resulting in elevated CS. Control sows (n = 8) were given no treatment while the treatment sows (n = 8) were administered an i.v. injection of ACTH (1 IU/kg BW) weekly from 6 to 12 wk of gestation. A pig from each sow was sacrificed at 1, 30 and 60 d of age. From these pigs, pituitary corticotrope and somatotrope numbers and adrenal gland cortex-to-medulla ratio (CORT:MED) were quantified. Pig behavior was recorded at 6 and 8 wk of age. At 75 d of age, plasma CS was determined and a biopsy puncture was created on one pig from each litter, then pigs were stressed by mixing. Every other day for 10 d, plasma CS was obtained and biopsy damage was evaluated for healing. The number of corticotropes and somatotropes in pituitary sections was similar between treatments at 1, 30 and 60 d of age. The CORT:MED was less in control pigs compared to ACTH pigs at 1 and 60 d of age (P <.04), but at 30 d of age there was no treatment difference. At 8 wk of age, control pigs performed a higher frequency of belly nosing (P=.07) and oral vice behaviors (P=.01). In response to mixing stress, control pigs had lower plasma CS (P=.03) and healed faster (P=.006) than ACTH pigs. Thus, if exogenous ACTH administration to pregnant dams replicates the effects of prenatal stress, then chronic stress to a sow during gestation may cause developmental alterations to her offspring which may compromise their health and welfare later in life.