Table 3.

Previously proposed amino acid compositions for ideal proteins for 10–20 kg growing pigs¹ (% of lysine)

Amino acid	Amino acid content in the carcass2	ARC (1981) Ref.[39]3	Wang-Fuller (1989) Ref.[44]4,a	Chung-Baker (1992) Ref.[45]4,b	NRC (1998) Ref.[40]5,b	Baker (2000) Ref.[46]4,b
Arginine	91	---	---	42	42	42
Glycine	---	---	---	100	---	---
Histidine	47	33	---	32	32	32
Isoleucine	53	55	60	60	54	60
Leucine	111	100	110	100	102	100
Lysine	100	100	100	100	100	100
Met + Cys	49	50	63	60c	57e	60c
Phe + Tyr	100	96	120	95d	94f	95d
Proline	---	---	---	33	---	---
Tryptophan	12	15	18	18	19	17
Threonine	61	60	72	65	62	65
Valine	72	70	75	68	68	68
Glutamate6	---	---	826	878	---	---

¹These ratios are based on true digestible levels of amino acids in diets [40,44-46], except for ARC (1981) [36]. Except for glycine, all amino acids are L-isomers.

²Taken from Baker (1997) [38]. The body proteins in 20–45 kg pigs contain 63 g lysine/16 g nitrogen [38].

³These ratios are based on total amino acids in the diet. The total level of lysine in the diet is 1.10% (as-fed basis; 90% dry matter).

⁴The diet contains 1.20% true digestible lysine (as-fed basis; 90% dry matter).

⁵The diet contains 1.01% true digestible lysine (as-fed basis; 90% dry matter).

⁶Provided as the nitrogenous source for synthesis of other NEAA in animals.

^aDietary requirements are for 25–50 kg gilts.

^bDietary requirements are for 10–20 kg pigs.

^cThe ratio of L-methionine to L-cystine is 1:1.

^dThe ratio of L-phenylalanine to L-tyrosine is 53:47.

^eThe ratio of L-methionine to L-cystine is 47:53.

^fThe ratio of L-phenylalanine to L-tyrosine is 64:36.