Table 1.

Mean, standard deviation, and ranges for cortisol concentrations in mother’s milk at early and peak lactation (1 month and 3–4 months postpartum, respectively) and the calculated change (Δ) per day between the 2 time points for rhesus macaques (N = 108)

Time point	Concentration (nmol/L)
	Mean	SD	Range
Early	175.5	86.7	19–444
Peak	172.7	97.3	21–622
Δ per day	−0.06	1.2	−4.5 to 2.8