Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2000
Publication Date: N/A
Technical Abstract: Previously, we reported that caesarian delivery reduces average daily gain and serum insulin-like growth factor 1 (IGF-1) in neonatal pigs. The objective of this study was to determine whether dexamethasone (Dex; a potent synthetic glucocorticoid) treatment at birth would alter postnatal growth in pigs. Forty crossbred pigs were injected i.m. with either saline e(Cont; n=10 males/10 females) or Dex (1 mg/kg; n=10 males/10 females) within 1 h of birth. All pigs remained with their respective dams until 18 d of age. Body weights were recorded weekly and on d 18. On d 17, pigs were nonsurgically fitted with an indwelling jugular catheter and returned to the sows. On d 18, pigs were placed in individual pens for blood collection. Birth weights (1.53+/.04 kg) did not differ between birth treatments or sex classes (P>0.70 and 0.89, respectively). A time by birth treatment effect was detected (P<0.007) for body weight such that those pigs which received Dex at birth had the greatest body weights during the 18-d period. Average daily gain was increased (P<0.017) by 12.2% in those pigs which received Dex at birth (.286+/.007) as compared to the Cont pigs (.255+/.01 kg/d). Serum IGF-1 was influenced by both birth treatment (P=0.0006) and sex class (P<0.017). Dex increased (P=0.02) serum IGF-1 by 40.5% in male pigs; and in females, Dex increased (P<0.007) serum IGF-1 by 33.5%. Results of this study, as well as previous reports from our laboratory, indicate that the early neonatal period may be an opportune time to permanently alter physiological factors which influence the growth biology of swine. Also, the results indicate that early neonatal hormonal therapies may be useful in achieving the actual genetic potential for growth in pigs.