Fetal hormone and metabolite levels in lean and obese pigs

Early development changes in hormone levels were investigated in strains of pigs with genetic propensities for excessive lipid deposition. Fetal serum growth hormone was lowest in the preobese pigs (Ossabaw and high backfat). Fetal serum triiodothyronine was significantly elevated in the fetal pigs from obese strains. Fetal serum cortisol was highest in the high backfat pigs. There were no statistically significant differences in fetal serum glucagon. Ossabaw (obese) sows have higher serum glucose levels during gestation than low backfat or high backfat sows. This hyperglycemia is reflected in higher serum glucose levels in 110 day old Ossabaw fetal pigs. High backfat sows have higher serum triglyceride levels that low backfat or Ossabaw sows. The Ossabaw fetal pig has lower serum triglycerides than either the high backfat or the low backfat fetuses. These studies characterize early changes in serum metabolites and hormones in pigs which have the genetic propensity for obesity. At 110 days of gestation these pigs are similar in body at content (less than 1%). It is proposed that the lower level of growth hormone in the preobese fetal pig promoted a lower rate of lean body growth and a higher rate of lipid deposition postnatally.