|Lay, Jr, Donald - Don|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2006
Publication Date: 7/9/2006
Citation: Schenck, E.L., Lay Jr, D.C., Kattesh, H.G., Cunnick, J.E., Daniels, M.J., Toscano, M.J., Mcmunn, K.A. 2006. The effects of prenatal stress on the ano-genital distance and growth hormone immuno-positive cells in the pituitary gland of the pig. Journal of Animal Science. 84(1):413.
Technical Abstract: Exposing pregnant mammals to prenatal stress has been shown to alter the stress response of their resulting offspring. Research in rodents has shown that prenatal stress can modify aspects of gender behavior and morphology. Our objective was to determine if prenatal stress altered the ano-genital distance and pituitary gland of piglets. Sow treatments consisted of i.v. injections of adrenocorticotrophin, 1 IU/kg BW, (ACTH, n=11), exposure to rough handling for a 10-min duration (ROU, n=13), or no treatment (CONT, n=13) once a week during d 42 to d 77 of gestation. Ano-genital distance (a ratio of body length:ano-genital distance) was measured after birth in all male piglets. One male piglet per dam was sacrificed at 2-mo of age and the pituitary gland was collected for immunocytochemistry for analysis of growth hormone. Male piglets born to dams who received ACTH had a larger ano-genital ratio (a smaller ano-genital distance) compared to piglets from the roughly handled sows or the control sows (p<0.0001; 2.01±.03; 1.91±0.3; 1.87±.02 respectively). There were no differences (p>0.1) among treatment groups in the number of immuno-positive cells for growth hormone in the pituitary gland. Adjusted weaning weight was found to be greater for pigs born to the control and roughly handled sows as compared to piglets from sows who received ACTH (p<.05). These data indicate that prenatal stress may decrease masculinization during development and possibly decrease reproductive success later in life. The weight differences in the ACTH group at weaning may be due to the high level of prenatal stress activated by the ACTH injections. The differences in weight may imply that an increase in prenatal stress (ACTH) alters pre-weaning weight gain; however, a 2-mo period appears to be sufficient for the quantity of pituitary cells positive for growth hormone to recover from stress. Future research is needed to assess the implications of the shortened ano-genital distance.