Impact of nutritional restriction of pregnant rabbits on thyroid function of offspring


This study aims to examine the effect of maternal feed supplemented with high and low protein ratio on fetal growth thyroid functions during newborn life. Thirty pregnant females were divided into control, fed on standard diet, and two treated groups, fed on a diet supplemented with 70% (T1) and 240% (T2) of crude protein during the gestational period. Birth weight and body weight gain of newborns were recorded. Serum thyroid hormones (TT3, TT4, FT3, FT4 and TSH) concentrations of neonates were measured at birth, 7, 14, and 21 days. The results of neonate birth weight revealed significant increase of T1 group and significant decrease of T2 group compared with control. T1 group newborns showed significant decline of body weight gain during experimental periods, whereas T2 group showed no significant difference at first and second weeks and significant decrease at third week. The highest body weight, at the end of third week of the newborn life, was recorded in control group, whereas the lowest body weight was recorded in T1 group. Serum levels of TSH, TT3, FT3, TT4, and FT4 of T1 group were significantly lower among experimental groups, at all experimental periods, whereas those of T2 group were higher than that of T1 group but still lower than that of control group. In conclusion, postnatal growth in the rabbit is partly result from a relative increase in FT3 in neonate plasma at birth, also neonates are, particularly susceptible to exposure to a low-protein maternal feed during the gestational period.