(A) Estimated least-square means and 95% confidence intervals of high-frequency power (HF; Hz) for 6-week (6W), 3-month (3M) and 6-month (6M) old calves undergoing CAST (square) and SHAM (triangle) (B) Time points evaluated consist of baseline (5 min before treatment; Base), early recovery (0–5 min after treatment; R05), middle recovery (5–10 min after treatment; R510), and late recovery (10–20 min after treatment; R1020).For LFP, there was no evidence for any differences between age groups or treatments over time. For LFP/HFP, evidence for a main effect of age was noted (p = 0.0059), whereby 6M old calves (estimated least square mean, [95% confidence interval]: 5.35 n.u., [2.75, 10.43]) showed greater LFP/HFP than younger calves (6W: 0.74 n.u., [0.41, 1.33], p = 0.0058; 3M: 1.22 n.u., [0.89, 1.67], p = 0.0044) regardless of SHAM or CAST.