Responses to saline drinking water in offspring born to ewes fed high salt during pregnancy

Abstract

We have studied the fetal programming of lambs born to ewes exposed to high salt during pregnancy. In the present study, we hypothesise that salt-programmed lambs may not need to drink as much saline water as control lambs and that voluntary feed intake of salt-programmed lambs would be reduced. We used two groups of lambs born to ewes fed either a high salt (13% NaCl) diet during pregnancy (S-lambs; n=12) or control animals born to ewes fed a conventional (0.5% NaCl) diet during pregnancy (C-lambs; n=12). Animals were offered ad libitum amounts of saline drinking water containing 1.5% NaCl for 2 days. Results indicated that there was a significant difference between fetal origin of the lamb (i.e. between C and S-lambs) and time (day 1 and 2) on water intake (P=0.055), urinary output (P=0.002), and sodium excretion (P=0.002). There was an interaction between fetal origin of the lambs and time (day 1 and 2) on the area under the curve (AUC) for the plasma concentration of aldosterone (P=0.017). Aldosterone concentration for C-lambs ranged from 167 to 196pg/ml over days 1 and 2, whilst S-lambs reduced their aldosterone by two-thirds from day 1 to 2, from 214±24 to 74±8pg/ml. A novel result was a marked difference in feed intake between C and S-lambs, where S-lambs consumed approximately 0.5kg DM/day (35%) less than C-lambs which was associated with a decrease in insulin secretion with time in both S and C-lambs. In conclusion, feeding a high salt diet to pregnant ewes affected the physiological responses of their offspring to the consumption of saline water during a period of 2 days illustrating that fetal programming changed the temporal pattern of how the offspring adapt to a load of ingested salt.