Table 3.

Composition of experimental diets (as-fed basis), experiment 2^1,2

Dietary phases	One-phase	Two-phase		Three-phase			Four-phase
Lysine specification	100%	100%		100%			100%
Initial weight, kg	27	27	100	27	50	100	27	50	72	100
Final weight, kg	127	100	127	50	100	127	50	72	100	127
Ingredient, %
Corn	68.64	62.98	69.87	56.09	66.17	69.87	56.09	63.32	69.16	69.87
DDGS3	20.00	20.00	20.00	20.00	20.00	20.00	20.00	20.00	20.00	20.00
Soybean meal, 47% CP	7.68	13.39	7.19	20.33	10.51	7.19	20.33	13.37	7.64	7.19
Tallow	0.75	0.75	0.75	0.75	0.75	0.75	0.75	0.75	0.75	0.75
Monocalcium phosphate, 21% P	0.55	0.50	---	0.40	0.25	---	0.40	0.25	0.10	---
Calcium carbonate	1.23	1.20	1.10	1.20	1.15	1.10	1.20	1.13	1.18	1.10
Sodium chloride	0.35	0.35	0.35	0.35	0.35	0.35	0.35	0.35	0.35	0.35
L-Lysine HCl	0.50	0.50	0.45	0.50	0.50	0.45	0.50	0.50	0.50	0.45
dl-Methionine	—	0.03	—	0.07	0.01	—	0.07	0.03	—	—
l-Threonine	0.10	0.11	0.09	0.13	0.11	0.09	0.13	0.11	0.11	0.09
l-Tryptophan	0.05	0.04	0.05	0.04	0.04	0.05	0.04	0.04	0.05	0.05
Vitamin–trace mineral premix4	0.16	0.16	0.16	0.16	0.16	0.16	0.16	0.16	0.16	0.16
Total	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Calculated analysis
SID5 AAs, %
Lysine	0.82	0.96	0.77	1.13	0.89	0.77	1.13	0.96	0.82	0.77
Isoleucine:lysine	57	58	59	60	58	59	60	58	57	59
Leucine:lysine	166	156	176	147	161	176	147	156	166	176
Methionine:lysine	29	30	31	32	30	31	32	30	29	31
Methionine and cysteine:lysine	57	57	60	57	57	60	57	57	57	60
Threonine:lysine	63	63	64	63	63	64	63	63	64	64
Tryptophan:lysine	18.8	18.9	19.7	19.0	18.6	19.7	19.0	18.9	19.4	19.7
Valine:lysine	70	69	73	69	70	73	69	69	70	73
Total lysine, %	0.95	1.11	0.90	1.29	1.03	0.90	1.29	1.11	0.95	0.90
NE, kcal/kg	2,540	2,509	2,562	2,471	2,535	2,562	2,471	2,518	2,555	2,562
SID Lys:NE, g/Mcal	3.23	3.83	3.01	4.57	3.51	3.01	4.57	3.81	3.21	3.01
CP, %	14.7	17.0	14.5	19.9	15.8	14.5	19.9	17.0	14.7	14.5
Calcium, %	0.60	0.60	0.46	0.60	0.53	0.46	0.60	0.53	0.50	0.46
STTD6 phosphorus, %	0.38	0.38	0.27	0.38	0.33	0.27	0.38	0.33	0.29	0.27
Chemical analysis7
DM, %	88.2	88.1	87.9	89.0	88.2	87.5	88.9	88.0	88.6	87.1
CP, %	14.3	16.7	15.1	20.3	16.4	15.0	17.9	16.3	15.0	15.2
EE, %	4.2	4.2	4.6	4.1	4.5	4.5	4.3	4.3	4.5	4.1
NDF, %	10.0	10.4	10.2	10.4	9.9	10.3	10.8	9.8	10.0	9.6
Calcium, %	0.80	0.75	0.63	0.81	0.68	0.47	0.68	0.71	0.57	0.74
Phosphorus, %	0.49	0.51	0.38	0.51	0.44	0.37	0.46	0.44	0.40	0.36
Lysine, %	0.90	1.03	0.90	1.25	0.99	0.92	1.08	1.04	0.88	0.99

¹Experiment evaluated feeding strategies based on number of dietary phases (one, two, three, and four dietary phases) with lysine specifications at 100% of estimated requirement for growth rate for grow-finish pigs. Lysine specifications were derived from the genetic supplier’s lysine requirement prediction equation based on commercial experiments (Genus PIC; Gonçalves et al., 2017).

²Diets were fed ad libitum in meal form from 27.4 to 125.6 kg BW for 121 d. Lysine levels in experimental diets were achieved by changing the inclusion of soybean meal.

³DDGS = corn distillers dried grains with solubles.

⁴Provided per kilogram of premix: 3,527,360 IU vitamin A; 881,840 IU vitamin D; 17,637 IU vitamin E; 1,764 mg vitamin K; 15.4 mg vitamin B₁₂; 33,069 mg niacin; 11,023 mg pantothenic acid; 3,307 mg riboflavin; 74 g Zn from zinc sulfate; 74 g Fe from iron sulfate; 22 g Mn from manganese oxide; 11 g Cu from copper sulfate; 0.22 g I from calcium iodate; 0.20 g Se from sodium selenite; 500,000 FTU phytase from OptiPhos 2000 (Huvepharma Inc., Peachtree City, GA).

⁵SID = standardized ileal digestible.

⁶STTD = standardized total tract digestible.

⁷Representative samples of complete feed were collected from multiple feeders and composite samples were ground, subsampled, and analyzed (Ward Laboratories, Inc., Kearney, NE for proximate analysis and Ajinomoto Heartland, Inc., Chicago, IL for lysine analysis).