Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2000
Publication Date: N/A
Technical Abstract: Ten full term pregnant sows were selected for a study to compare function of the reproductive system of pigs born by Cesarean section (c-section) or natural-birth (n=5 for natural-birth and c-section). Gestation length and birth weight did not differ between natural-birth and c-section pigs. Blood and tissue samples were collected from 45 pigs at birth and 41 pigs at 14 d of age. Day 14 pigs received an i.v. injection of GnRH (2.5 ug/kg or saline at min 0, blood serum samples were collected at -60,-45,-30,-15, 0, 15, 30, 45, 60, 90 and 120 min, and tissue samples were collected following the 120 min sample. Serum cortisol (CS), ACTH, LH, and FSH were determined by RIA. Expression of GnRH, GnRH receptor, LH and FSH alpha and beta subunits, and LH and FSH receptor were determined by slot blot. Centrifuge clot-to-blood ratio was greater among natural-birth than c-section pigs at birth (P<.01) but did not differ at 14 d. Basal serum ACTH did not differ between c-section and natural-birth pigs at birth or 1 d, but basal serum CS was greater in c-section than natural-birth pigs at birth and 14 d (P<.02). Basal serum FSH decreased from birth to 14 d (P<.0001) and was greater in gilts than boars (P<.0001). Treatment with GnRH significantly increased FSH in gilts (P<.0001), but not in boars. Basal serum LH was not affected by birth type or age but was greater in boars than gilts (P<.0001). Interestingly, c-section boars had a much greater LH response to GnRH challenge than natural-birth boars (P<.01). Response of LH to GnRH challenge did not differ in gilts. Type of birth did not significantly affect expression of the mRNAs examined in the current study. These data indicate that c-section birth alters function of the reproductive system in male neonatal pigs.