Effect of dietary near ideal amino acid profile on heat production of lactating sows exposed to thermal neutral and heat stress conditions

Table 7 Feed intake and metabolic total heat production [kJ/(d·BW^0.75)] of lactating sows fed high crude protein (HCP; 192.4 g/kg crude protein) and low crude protein (LCP; 140.0 g/kg crude protein) diets and exposed to thermal neutral and heat stress conditions^a

Item	Thermal neutral				Heat stress
Item	HCP	LCP	SEM^b	P-value	HCP	LCP	SEM^b	P-value
Number of sows^c	6	6	–	–	6	6	–	–
Feed intake, kg/d^d
Day 4	4.96	4.46	–	–	5.23	4.83	0.46	0.536
Day 8	6.59	5.70	–	–	6.63	5.58	0.46	0.109
Day 14	6.93	6.57	–	–	6.97	6.56	0.46	0.524
Day 18^c	7.26	7.80	–	–	7.58	6.93	0.46	0.406
Metabolic total heat production
Nighttime (19:00–07:00)^e
Day 4	563.6	465.7	53.6	0.203	597.5	512.1	43.1	0.092
Day 8	568.2	533.0	53.6	0.645	589.9	538.9	41.4	0.263
Day 14	651.9	577.0	53.6	0.329	627.2	603.8	43.5	0.616
Day 18	612.1	493.7	58.6	0.145	573.6	457.3	41.0	0.013
Average	599.1	518.8	27.6	0.040	609.6	515.1	31.8	0.006
SEM^§b	28.6	42.8			61.1	16.3
Contrast^f	–	–			–	Q^*, D^†
Daytime (07:00–19:00)^e
Day 4	627.6	618.8	51.5	0.873	677.8	674.9	30.1	0.940
Day 8	729.7	682.8	51.5	0.393	692.5	658.6	28.5	0.410
Day 14	779.9	686.6	51.5	0.093	697.5	672.0	28.0	0.529
Day 18	724.7	664.8	54.4	0.301	711.3	544.8	28.0	< 0.001
Average	715.5	663.6	39.9	0.065	708.8	625.5	14.6	0.009
SEM^§b	26.3	49.0			17.2	22.2
Contrast^f	L^, Q^, D^†	–			–	L^, Q^, D^*
Overall 24 h
Day 4	595.4	542.2	48.1	0.377	643.5	592.0	29.7	0.184
Day 8	648.9	607.9	48.1	0.494	640.2	597.5	28.5	0.259
Day 14	715.9	631.8	48.1	0.165	661.5	638.9	28.0	0.542
Day 18	668.6	579.9	51.9	0.164	641.4	500.0	28.0	< 0.001
Average	657.3	591.2	32.2	0.033	659.8	571.1	17.6	0.002
SEM^§b	21.5	45.9			38.9	11.3
Contrast^f	–	–			–	Q^, D^

^aData are least squares means
^bMaximum value of the standard error of the means
^cOne LCP sow under TN was missing for calorimetry day 18 and one LCP sow under HS completed calorimetry day 18 from 07:00 until 12:00
^dFeed intake under TN was fixed and pair fed to counterparts under HS, and thus no SEM and P value were included
^eMetabolic total heat production between nighttime and daytime differs under TN and HS conditions (P < 0.01)
^fLinear, quadratic contrast and day effect on total heat production along lactation (d 4, 8, 14 and 18) was performed and represented as L, Q, and D, respectively
^§Standard error of the means for contrast over days 4, 8, 14 and 18
^* Within the same diet, environments differed (P < 0.05)
^† Within the same diet, environments tended to differ (0.05 < P ≤ 0.10)

ISSN: 2049-1891