. 2015 May 4;10(5):e0125264. doi: 10.1371/journal.pone.0125264

Table 3. Effects of heat stress (HS) or pair-feeding (PF) on nutritional, vital and metabolic variables.

		P1		P2		Covariance	P-Value
Item	Stage	HS	PF	HS	PF	structure	Group	Day	Group*Day
DMI, kg	ap	10.63 ±0.93	11.3 ±0.27	6.67 ±0.69	6.82 ±0.72	AR	0.557	0.021	0.957
DMI, kg	pp	16.35 ±0.86	15.19 ±0.42	10.12 ±0.85	9.78 ±0.89	AR	0.515	<0.001	0.795
Milk yield, L	pp	32.95 ±1.86	36.42 ±1.47	26.54 ±1.68	28.96 ±2.04	AR	0.476	<0.001	0.648
Water intake/DMI, L/kg	ap	2.44 ±0.26	2.7 ±0.28	6.03 ±0.66	3.81 ±0.77	CS	0.034	0.108	0.064
Water intake/DMI, L/kg	pp	4.41 ±0.26	4.59 ±0.27	6.85 ±0.86	5.58 ±0.35	AR	0.010	0.221	0.517
Rectal temperature, °C	ap	38.81 ±0.14	38.53 ±0.07	39.53 ±0.23	38.72 ±0.21	AR	0.081	0.958	0.030
Rectal temperature, °C	pp	38.88 ±0.14	38.43 ±0.17	40.09 ±0.18	38.33 ±0.2	CS	0.000	0.033	0.005
Heart rate, counts/minute	ap	87.38 ±3.5	79 ±2.58	83.66 ±6.87	75.07 ±4.86	AR	0.647	0.136	0.103
Heart rate, counts/minute	pp	80.75 ±2.21	81.94 ±3.96	83.04 ±2.88	74.76 ±3.7	AR	0.020	0.095	0.091
Respiratory rate, counts/minute	ap	38.7 ±2.51	36.67 ±5.27	82.26 ±4.99	36.85 ±3.63	AR	<0.001	0.077	0.433
Respiratory rate, counts/minute	pp	33.36 ±2.35	42.28 ±2.58	81.81 ±5.57	28.08 ±2.56	AR	<0.001	0.098	0.971
Hematocrit, %	ap	34.05 ±0.82	33.5 ±1.14	32.35 ±0.73	32.28 ±1.05	AR	0.234	0.021	0.422
Hematocrit, %	pp	31.28 ±0.91	28.89 ±0.86	28.19 ±1.18	29.17 ±0.91	CS	0.009	0.001	0.004
Glucose, mmol/L	ap	3.94 ±0.15	3.56 ±0.08	3.63 ±0.05	3.27 ±0.15	CS	0.912	<0.001	0.016
Glucose, mmol/L	pp	3.31 ±0.26	3.09 ±0.11	2.82 ±0.24	2.49 ±0.22	AR	0.552	0.002	0.656
BHBA, mmol/L	ap	0.48 ±0.04	0.47 ±0.03	0.59 ±0.04	0.57 ±0.12	CS	0.979	0.038	0.594
BHBA, mmol/L	pp	1.18 ±0.25	0.94 ±0.19	1.85 ±0.55	2.04 ±0.45	AR	0.384	0.004	0.922
NEFA, μmol/L	ap	182.29 ±30.65	179.44 ±23.2	506.79 ±77.62	603.83 ±140.57	AR	0.435	0.002	0.600
NEFA, μmol/L	pp	749.06 ±118.42	720.17 ±119.91	856.39 ±127.43	1205.75 ±185.39	AR	0.016	<0.001	0.165
Urea, mmol/L	ap	3.88 ±0.39	2.86 ±0.28	3.78 ±0.36	3.07 ±0.26	AR	0.059	0.060	0.981
Urea, mmol/L	pp	3.59 ±0.38	3.15 ±0.14	5.18 ±0.66	3.57 ±0.22	AR	0.027	0.061	0.461
Creatinine, μmol/L	ap	93.78 ±4.02	91.39 ±5.67	113.87 ±5.12	97.92 ±5.27	AR	0.001	0.022	0.023
Creatinine, μmol/L	pp	80.3 ±4.38	77.27 ±3.13	104.44 ±7.91	75.97 ±2.78	CS	0.001	0.007	0.021
Urea/Creatinine-Ratio, mmol/μmol	ap	0.0417 ±0.0042	0.0323 ±0.0043	0.0336 ±0.0031	0.0310 ±0.0024	CS	0.022	<0.001	0.187
Urea/Creatinine-Ratio, mmol/μmol	pp	0.0445 ±0.0039	0.0411 ±0.0021	0.0494 ±0.0057	0.0471 ±0.004	AR	0.702	0.429	0.452
Noradrenaline, pg/mL	ap	199.33 ±25.7	250.68 ±28.61	252.37 ±32.89	204.26 ±24.61	AR	0.011	0.566	0.183
Noradrenaline, pg/mL	pp	178.32 ±20.47	228.4 ±40.52	255.4 ±34.61	227.13 ±47.77	AR	0.079	0.302	0.271
Adrenaline, pg/mL	ap	71.16 ±4.27	97.36 ±10.33	89.04 ±10.83	89.63 ±16.04	CS	0.119	0.277	0.508
Adrenaline, pg/mL	pp	80.18 ±5.6	64.29 ±8.28	104.79 ±11.42	52.62 ±6.29	CS	0.008	0.510	0.066

ap ante partum; pp post-partum; P1 period of thermoneutral conditions (THI = 59.7) with ad libitum feeding; P2 period of either pair feeding at thermoneutral (THI = 60.0) conditions (PF) or during ad libitum feeding under heat exposure (HS, THI = 76.1); values given as mean ±standard error of mean; AR autoregressive; CS compound symmetric.

Numbers of animals analyzed per group: HSap n = 7, PF ap n = 6, HS pp n = 6, PF pp n = 6.