Table 2. mRNA expression of peripheral blood leukocytes isolated from dairy calves at 1, 21 and 42 days of age.

Gene	mRNA expression of CL relative to HS calvesa
	day 1	day 21	day 42	P-valuec
	Log2FCb ± SEM	Log2FC ± SEM	Log2FC ± SEM	Trt	day	Trt×day
HSF1	0.12 ± 0.35	0.70 ± 0.35	0.04 ± 0.36	0.14	0.32	0.44
HSP70	0.57 ± 0.17	0.73 ± 0.12	0.58 ± 0.10	0.02	0.56	0.29
HSP72	-0.22 ± 0.27	-0.19 ± 0.27	-0.12 ± 0.27	0.24	0.33	0.94
HSP90	-0.13 ± 0.26	-0.36 ± 0.28	0.13 ± 0.27	0.36	0.01	0.42
RORgd	-0.63 ± 1.84	-1.83 ± 1.89	0.94 ± 1.86	0.58	0.01	0.45
FoxP3	0.90 ± 0.35	0.40 ± 0.35	0.17 ± 0.36	0.10	< .0001	0.33
GATA3	0.34 ± 0.33	0.08 ± 0.33	-0.16 ± 0.34	0.86	< .0001	0.54
TBX21	0.64 ± 0.44	0.72 ± 0.45	0.72 ± 0.45	0.05	< .0001	0.98
CD62L	-0.65 ± 0.46	0.80 ± 0.53	-0.47 ± 0.49	0.68	0.04	0.24
CD25	-0.35 ± 0.49	0.47 ± 0.53	-0.20 ± 0.53	0.89	< .0001	0.36
CD28	0.56 ± 0.39	0.00 ± 0.39	-0.04 ± 0.40	0.70	< .0001	0.43
CD80	0.45 ± 0.40	0.31 ± 0.40	0.13 ± 0.41	0.19	0.24	0.86
TLR2	0.45 ± 0.55	0.77 ± 0.57	0.17 ± 0.59	0.22	0.77	0.76
TLR4	0.94 ± 0.44	0.31 ± 0.45	0.32 ± 0.46	0.02	0.86	0.52
BCL2A1	-0.43 ± 0.67	-0.55 ± 0.67	0.35 ± 0.69	0.65	0.10	0.54
BAX	0.18 ± 0.29	0.02 ± 0.31	0.41 ± 0.29	0.48	< .0001	0.60
TGFB1	0.78 ± 0.31	0.57 ± 0.32	0.52 ± 0.32	<0.01	0.03	0.73
IFNG	1.10 ± 0.68	-0.06 ± 0.67	0.51 ± 0.66	0.66	< .0001	0.44
TNFA	0.13 ± 0.39	0.21 ± 0.39	0.07 ± 0.40	0.69	0.58	0.96
IL1B	-0.16 ± 0.60	-0.11 ± 0.63	-0.07 ± 0.65	0.72	0.28	0.99
IL2	0.32 ± 0.32	-0.41 ± 0.34	0.22 ± 0.32	0.15	< .0001	0.47
IL4	-1.07 ± 0.07	-1.11 ± 0.07	1.00 ± 0.07	0.21	< .0001	0.44
IL10	-0.03 ± 0.49	0.16 ± 0.51	-0.40 ± 0.53	0.85	0.02	0.76
IL12B	-0.35 ± 0.56	-0.16 ± 0.56	-0.64 ± 0.58	0.41	<0.01	0.80
SERT	0.85 ± 0.57	0.06 ± 0.58	0.37 ± 0.61	0.29	0.14	0.58
TPH1	-2.13 ± 0.49	-0.46 ± 0.46	0.05 ± 0.50	<0.01	0.67	0.01
5HT1A	-3.35 ± 0.95	-2.00 ± 0.90	-1.41 ± 1.41	<0.01	< .0001	0.35
5HT1B	-2.09 ± 0.50	-1.11 ± 0.47	-0.01 ± 0.49	0.01	0.23	0.02
5HT1D	-3.28 ± 0.53	-1.22 ± 0.51	0.06 ± 0.53	<0.01	< .0001	<0.01
5HT1F	-2.34 ± 0.56	-1.19 ± 0.56	-0.35 ± 0.58	0.01	< .0001	0.06
5HT2A	1.14 ± 0.59	0.01 ± 0.62	1.13 ± 0.64	0.03	0.05	0.46
5HT2B	-0.52 ± 0.38	0.07 ± 0.38	-0.15 ± 0.41	0.34	0.35	0.57
5HT2C	-3.51 ± 0.54	-1.26 ± 0.50	0.99 ± 0.52	0.01	< .0001	< .0001
5HT4	-3.02 ± 0.76	-2.02 ± 0.76	-0.77 ± 0.82	<0.01	0.08	0.14
5HT5	-2.95 ± 0.98	-2.31 ± 0.98	-0.43 ± 1.05	0.02	0.01	0.15
5HT6	-1.58 ± 0.43	-0.72 ± 0.45	0.56 ± 0.47	0.05	0.69	0.01
5HT7	-1.83 ± 0.40	-1.53 ± 0.40	0.05 ± 0.41	<0.01	0.60	0.01

^a Calves were exposed to heat stress (HS; n = 6) or heat stress abatement (CL; n = 6) treatments (Trt) across pre- and postnatal periods (late gestation and pre-weaning) for a total of 102 d.

^b Gene expression is presented as Log₂ Fold Change (Log₂FC) of CL relative to HS calves at d 1, 21 and 42 postnatal using the LSM ± SEM of the interaction treatment (Trt) × day.

^c Significance was declared at P ≤ 0.05 (bold) and tendencies at 0.05 < P ≤ 0.10.