Table 1.

Ingredient composition and nutrient content of control (CON), ptimal (OPT) and Optimal + leucine (OPTLEU) diets (g/kg, as-fed basis)

	CON	OPT	OPTLEU
Ingredient composition
Corn, yellow dent	591.7	614.5	612.1
Soybean meal1	300.0	140.0	140.0
Soy hulls	–	105.7	105.7
Sugar food product2	50.0	50.0	50.0
Beef tallow	33.5	50.2	48.1
L-Lysine·HCl, 78.8%	–	4.7	4.7
L-Valine	–	2.9	2.9
L-Threonine	–	2.0	2.0
L-Phenylalanine	–	1.3	1.3
DL-Methionine	–	1.1	1.1
L-Isoleucine	–	0.8	0.8
L-Histidine	–	0.7	0.7
L-Tryptophan	–	0.5	0.5
L-Leucine	–	–	4.5
Limestone	11.8	9.3	9.3
Dicalcium phosphate	4.5	7.8	7.8
Sodium chloride	5.0	5.0	5.0
Vitamin and mineral Premix3	2.5	2.5	2.5
Titanium dioxide	1.0	1.0	1.0
Calculated nutrient4
Net energy, MJ/kg	10.8	10.8	10.8
Crude protein	192.4	140.0	143.4
Fermentable fiber	115.8	115.8	115.7
SID5 amino acids
Arginine	11.7	7.1	7.1
Histidine	4.7	3.7	3.7
Isoleucine	7.1	5.2	5.2
Leucine	14.7	10.3	14.7
Lysine	9.0	9.0	9.0
Methionine6	2.7	3.0	3.0
Methionine + cysteine	5.4	4.9	4.9
Phenylalanine	8.4	6.7	6.7
Phenylalanine + tyrosine	13.8	10.3	10.3
Threonine	6.1	5.8	5.8
Tryptophan	2.1	1.7	1.7
Valine	7.7	7.9	7.9
Nitrogen	26.3	18.8	19.3
Total calcium7	6.5	6.5	6.5
STTD8 phosphorus7	2.3	2.3	2.3

¹480 g/kg crude protein

²Supplied per kg: net energy 11.9 MJ; fermentable fiber 0.5 g/kg; crude protein 10 g/kg (International Ingredient Corporation, St. Louis, MO, USA)

³Sow micro 5 and Se-yeast PIDX15 (Provimi North America, Inc. Brookville, OH, USA)

⁴Based on nutrient concentrations in feed ingredients according to NRC [13]

⁵SID: standardized ileal digestible

⁶Methionine concentration in Optimal and Optimal + Leucine is higher than Control because methionine was added to meet requirement of (methionine + cysteine)

⁷Additional calcium (1.0 g/kg) and phosphorus (1.5 g/kg) releases were accounted due to phytase from the premix

⁸STTD: standard total tract digestible