Table 1.

Diet composition, Exp. 1 and 2 (as-fed basis)¹

	Exp. 1		Exp. 2
Item	0.26% STTD P2	0.53% STTD P	0.30% STTD P	0.58% STTD P
Ingredients, %
Corn	64.95	63.10	65.79	63.73
Soybean meal, 46,5% CP	31.72	31.85	31.66	31.80
Monocalcium phosphate, 21% P	0.52	1.92	0.00	1.60
Limestone	1.00	1.30	0.74	1.05
Sodium chloride	0.60	0.60	0.65	0.65
L-Lysine HCl	0.48	0.48	0.48	0.48
DL-Methionine	0.21	0.21	0.21	0.21
L-Threonine	0.16	0.16	0.16	0.16
L-Tryptophan	0.03	0.03	0.03	0.03
L-Valine	0.08	0.08	0.08	0.08
Phytase3	–	–	0.04	0.04
Vitamin premix4	0.13	0.13	–	–
Trace mineral premix5	0.10	0.10	–	–
Vitamin and trace mineral premix6	–	–	0.15	0.15
Copper chloride7	0.04	0.04	0.04	0.04
Total	100	100	100	100
Calculated analysis
Standardized ileal digestible amino acids, %
Lysine	1.33	1.33	1.33	1.33
Isoleucine:lysine	57	56	57	57
Leucine:lysine	117	116	117	116
Metthionine:lysine	37	37	37	37
Methionine and cysteine:lysine	58	58	58	58
Threonine:lysine	60	60	60	60
Tryptophan:lysine	19	19	19.1	19.1
Valine:lysine	67	67	67	67
Net energy, kcal/kg	2,429	2,385	2,452	2,401
Crude protein, %	21.3	21.2	20.5	20.4
Calcium, %	0.59	0.94	0.47	0.84
Phosphorus, %	0.51	0.80	0.40	0.71
Standardized total tract digestible phosphorus, %	0.26	0.53	0.30	0.58
Available phosphorus, %	0.19	0.49	0.23	0.54
Calcium:phosphorus	1.17	1.18	1.17	1.17

¹In Exp. 1, diets were fed from 11.4- to 22.8-kg BW. Diets were blended to form the intermediate treatments: 0.30, 0.33, 0.38, 0.43, and 0.48% STTD P. In Exp. 2, diets were fed from 11.1- to 22.5- kg BW. Diets were blended to form the intermediate treatments: 0.33, 0.38, 0.43, 0.48, and 0.53% STTD P.

²STTD P = standardized total tract digestible phosphorus.

³Ronozyme HiPhos 2500 (DSM Nutritional Products, Parsippany, NJ) provided 1,000 FYT per kg of feed, releasing an assumed 0.15% avP and 0.132% STTD P.

⁴Provided per kg of premix: 8,818,490 IU vitamin A; 1,102,311 IU vitamin D; 35,273 IU vitamin E; 3,527.4 mg vitamin K; 30.9 mg vitamin B12; 39,683 mg niacin; 22,046 mg pantothenic acid; 6,614 mg riboflavin.

⁵Provided per kg of premix: 165 g Zn from Zn sulfate; 165 g Fe from iron sulfate; 40 g Mn from manganese oxide; 17 g Cu from copper sulfate; 0.3 g I from calcium iodate; 0.3 g Se from sodium selenite.

⁶Provided per kg of premix: 5,346,210 IU vitamin A; 1,338,206 IU vitamin D; 100,211 IU vitamin E; 1,671.1 mg vitamin K; 21.4 mg vitamin B12; 29,061 mg niacin; 15,366 mg pantothenic acid; 4,008 mg riboflavin, 73.5 g Zn from Zn sulfate; 66.8 g Fe from iron sulfate; 26.7 g Mn from manganese oxide; 10 g Cu from copper sulfate; 0.5 g I from calcium iodate; 0.2 g Se from sodium selenite.

⁷Supplemental copper provided in the form of tri-basic copper chloride (TBCC; Intellibond C; Micronutrients, Indianapolis, IN) at 150 ppm.