0023-6152

AA00697606

1909903

It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring’s body weight. However, the negative effects of maternal stress on the mother’s milk, which is one of the most important connecting factors between mothers and their offspring, are not yet fully understood. The present study aimed to investigate how free amino acids in milk, as well as the growth and behavior of offspring, are changed by maternal stress during the gestation and lactation periods. Although maternal stress during the gestation period did not affect the growth of offspring or the free amino acid composition in the milk, the offspring in the stressed group showed lower locomotor activity. However, maternal stress during the lactation period caused a reduction in body weight in the offspring following the stress load. It increased the concentration in the milk of several amino acids, such as taurine, aspartic acid and β–alanine, while it decreased the concentration of most of the free amino acids in the maternal plasma. Notably, the body weight of offspring at postnatal age 11 days was negatively correlated with taurine concentration in the milk. These results show that maternal stress during the lactation period may have a great impact on the free amino acid composition of the milk, which may partly, but not entirely, be the cause of lower body weight in the offspring.