Reduced protein diet with near ideal amino acid profile improves energy efficiency and mitigate heat production associated with lactation in sows

Table 6 Dietary energy partitioning of sows fed Control (CON; 187.4 g/kg crude protein), Optimal (OPT; 137.8 g/kg crude protein) or Optimal + Leucine (OPTLEU; 142.5 g/kg) diets between day 4 and 8 of lactation (early lactation) and between day 14 and 18 of lactation (peak lactation)¹

Item	Diet			SEM²	P-value
Item	CON	OPT	OPTLEU	SEM²	OPT vs. CON	OPT LEU vs. CON	OPTLEU vs. OPT
Early lactation (day 4 to 8)
Number of sows	12	11	11
Feed intake, kg/d	4.9	4.9	4.6	0.10	0.899	0.102	0.135
Gross energy (GE), MJ/kg
Analyzed	17.24	17.10	17.33	–	–	–	–
Calculated	17.22	17.58	17.57
Digestible energy (DE), MJ/kg
Analyzed	15.22	14.90	14.77	0.10	0.062	0.006	0.571
Calculated	15.03	14.70	14.71
Metabolizable energy (ME), MJ/kg
Analyzed	14.84	14.64	14.52	0.20	0.766	0.507	0.904
Calculated	14.44	14.26	14.26
Corrected net energy (NE_c), MJ/kg³	11.56	11.36	12.63	0.69	0.977	0.511	0.405
NE_lactation⁴	7.65	7.28	8.57	0.71	0.928	0.625	0.417
NE_maintenance⁵	3.91	4.07	4.16	0.15	0.536	0.233	0.822
Calculated	10.80	10.80	10.80
Peak lactation (day 14 to 18)
No. of sows	11	11	11
Feed intake, kg/d	6.8	6.7	6.3	0.1	0.865	0.034	0.049
Gross energy (GE), MJ/kg
Analyzed	17.24	17.10	17.33	–	–	–	–
Calculated	17.22	17.58	17.57
Digestible energy (DE), MJ/kg
Analyzed	15.22	14.90	14.77	0.10	0.062	0.006	0.571
Calculated	15.03	14.70	14.71
Metabolizable energy (ME), MJ/kg
Analyzed	14.81	14.67	14.45	0.20	0.887	0.427	0.709
Calculated	14.44	14.26	14.26
Corrected net energy (NE_c), MJ/kg³	10.01^*	12.16	11.25	0.69	0.087	0.418	0.623
NE_lactation⁴	7.13	9.26^*	8.13	0.71	0.105	0.584	0.506
NE_maintenance⁵	2.88^*	2.93	3.14	0.15	0.952	0.221	0.349
Calculated	10.80	10.80	10.80

¹Data are least squares means; energy is presented as MJ/kg feed
²Maximum value of the standard error of the means
³ NE_c(MJ/kg feed ) = NE_milk(MJ/kg feed) + NE_maintenance(MJ/kg feed). NE was higher (P < 0.05) than calculated NE in OPTLEU diet during early lactation and tended to be higher (P = 0.057) in OPT diet during peak lactation
⁴ \( {\mathrm{NE}}_{\mathrm{lactation}}\left(\mathrm{MJ}/\mathrm{kg}\ \mathrm{feed}\ \right)=\frac{\mathrm{Milk}\ \mathrm{energy}\ \mathrm{output}\left(\mathrm{MJ}/\mathrm{d}\right)-\mathrm{Milk}\ \mathrm{energy}\ \mathrm{from}\ \mathrm{body}\ \left(\mathrm{MJ}/\mathrm{d}\right)}{\mathrm{Daily}\ \mathrm{feed}\ \mathrm{intake}\left(\mathrm{kg}/\mathrm{d}\right)} \). NE_lactation was lower than (P < 0.01) calculated NE in each experimental diet during both early and peak lactation
⁵\( {\mathrm{NE}}_{\mathrm{maintenane}}\left(\mathrm{MJ}/\mathrm{kgfeed}\right)=\frac{0.310\times {\mathrm{BW}}^{0.75}\left(\mathrm{MJ}/\mathrm{d}\right)}{\mathrm{Daily}\kern0.34em \mathrm{feed}\kern0.34em \mathrm{intake}\left(\mathrm{kg}/\mathrm{d}\right)} \)
^*Main effect of period (early and late) was significant (P < 0.05).

ISSN: 2049-1891