Effects of mammalian in utero heat stress on adolescent body temperature

Figures & data

Figure 1. Effects of gestational and adolescent thermal environments on the temporal changes in (A) respiration rate (RR), (B) rectal temperature (T_re), and (C) T_re averaged by gestational and adolescent environment in growing pigs. Gestational heat stress (GHS), gestational thermal neutral (GTN), adolescent thermal neutral conditions (TN), adolescent heat stress conditions (HS). Error bars on day 1 and day 15 of the line indicate ±1 SEM. Different letters (a,b,c) above vertical bars in 1C indicate significant differences (p < 0.05).

Table I. Effects of gestational and adolescent thermal environments on body temperature indices in growing pigs.

	Environments					p
Parameter	GTN-TN^1	GHS-TN^2	GTN-HS^3	GHS-HS^4	SD	G^5	A^6	G × A
RR^7 (bpm)	52	45	93	90	23	0.14	<0.01	0.52
T^8re^9 (°C)	39.35^a	39.27^a	39.51^b	39.77^c	0.31	0.15	<0.01	<0.01
Tear (°C)	30.87	30.64	36.51	36.77	2.23	0.96	<0.01	0.39
Tshoulder (°C)	31.60	31.43	36.82	37.12	1.90	0.79	<0.01	0.26
Trump (°C)	31.36	31.30	37.33	37.50	1.85	0.86	<0.01	0.61
Ttail (°C)	31.42	31.31	36.99	37.27	1.85	0.66	<0.01	0.30
Tskin^10 (°C)	31.32	31.17	36.91	37.19	1.75	0.78	<0.01	0.33
TCI^11ear	1.09	1.02	1.24	0.92	1.48	0.14	0.84	0.30
TCIshoulder	1.21	1.16	1.71	1.42	3.07	0.29	0.06	0.32
TCIrump	1.19	1.10	1.58	1.90	3.66	0.46	<0.01	0.11
TCItail	1.15^a	1.14^a	0.84^a	2.10^b	2.74	0.03	0.25	0.02
TCIskin	1.12	1.07	1.51	1.78	2.07	0.38	<0.01	0.20

¹Gestational thermal neutral pigs in adolescent thermal neutral conditions

²Gestational heat stress pigs in adolescent thermal neutral conditions

³Gestational thermal neutral pigs in adolescent heat stress conditions

⁴Gestational heat stress pigs in adolescent heat stress conditions

⁵Gestational environment

⁶Adolescent environment

⁷Respiration rate

⁸Temperature

⁹Rectal

¹⁰Average skin temperature

¹¹Thermal circulation index

^a,b,cp < 0.05

Figure 2. Effects of gestational and adolescent thermal environments on the temporal changes in (A) ear skin temperature (T_ear), (B) shoulder skin temperature (T_shoulder), (C) rump skin temperature (T_rump), and (D) tail skin temperature (T_tail) in growing pigs. Gestational heat stress (GHS), gestational thermal neutral (GTN), adolescent thermal neutral conditions (TN), adolescent heat stress conditions (HS), adolescent conditions (AC). Error bars on day 1 and day 15 of the line indicate ±1 SEM. p Values in each figure represent T_skin differences comparing adolescent TN and HS exposed animals regardless of gestational treatment.

Figure 3. Linear regression (y = mx + b) of respiration rate (RR) as a function of rectal temperature (T_re) for gestational thermal neutral (GTN) and gestational heat stress (GHS) exposed pigs, regardless of adolescent environment. Coefficient of determination (R²), and slope (m) is presented for each regression line.

Table II. Effects of gestational and adolescent thermal environments on production parameters in growing pigs.

	Environments					p
Parameter	GTN-TN^1	GHS-TN^2	GTN-HS^3	GHS-HS^4	SD	G^5	A^6	G × A
Initial BW (kg)	68.5	66.3	67.3	63.5	4.6	0.17	0.31	0.68
Final BW (kg)	80.1	77.5	76.4	72.5	6.3	0.16	0.04	0.70
NI (kg/d)^8	2.87	2.89	2.24	2.07	0.56	0.71	<0.01	0.61
BW gain (kg/d)^7	0.92	0.75	0.68	0.42	0.29	0.16	0.04	0.70
Gain:Feed (kg/kg)^9	0.34	0.25	0.32	0.15	0.12	0.10	0.16	0.34

¹Gestational thermal neutral pigs in adolescent thermal neutral conditions

²Gestational heat stress pigs in adolescent thermal neutral conditions

³Gestational thermal neutral pigs in adolescent heat stress conditions

⁴Gestational heat stress pigs in adolescent heat stress conditions

⁵Gestational environment

⁶Adolescent environment

⁷Body weight gain

⁸Nutrient intake

⁹Feed efficiency