Indirect indicator of transport stress in hematological values in newly acquired cynomolgus monkeys

Indicators of transport stress were investigated in blood parameters of five male cynomolgus monkeys obtained from abroad. They underwent air and ground travel-related stress in transport cages for a 15-hour transit time. On arrival, hematological parameters of white blood cell count, red blood cell count, hemoglobin concentration, and hematocrit values were within the limits of reference range, indicating that these parameters were not typical changes derived from transport stress loading. An increase in neutrophil-to-lymphocyte (N/L) ratio with a marked increase in neutrophils and a decrease in lymphocytes was observed on arrival, and the increased N/L ratio returned approximately to the normal level 1 week after arrival. The serum cortisol level markedly increased on the day of arrival and it returned to normal 1 week after arrival. These findings indicate that the transport process was stressful for animals, showing increases in N/L ratio as well as cortisol level. Thus, it is possible that an increase in N/L ratio may be utilized as an indirect indicator of transport stress in newly acquired cynomolgus monkeys, as it has the similar pattern of change in cortisol with an increased cortisol level on the day of arrival.