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Table 5 Suggested minimum standardized ileal digestible amino acid ratios for growing swine 1

From: Practical starter pig amino acid requirements in relation to immunity, gut health and growth performance

 

Pig weight range, kg

Amino acid

4 to 25

25 to 40

40 to 60

60 to 80

80 to 100

100 to 130

Lysine

100

100

100

100

100

100

Threonine2

62

61

61

62

63

64

Methionine3

28

28

28

28

28

28

Methionine + cysteine4

58

56

56

56

57

58

Tryptophan 5

18+

18+

18+

18+

18+

18+

Isoleucine6

52

52

52

52

52

52

Valine

65

65

65

65

65

65

  1. 1Adapted from Shannon and Allee, [24] with updates from recent research conducted by the authors and summarized in this paper. Ratios are based on NRC [23] nutrient levels for ingredients. Nutritionists should review their ingredient nutrient values relative to NRC [23] to apply these ratios to their diets.
  2. 2Threonine:lysine = 0.0000130x2 - 0.0014229x + 0.6387290.
  3. 3Methionine:lysine = 0.0000020x2 - 0.0000808x + 0.2806061.
  4. 4Methionine & Cysteine: lysine = 0.0000113x2 - 0.0012621x + 0.5785238.
  5. 5Tryptopan:lysine ratio appears to be increased when the diet contains large excesses of large neutral amino acids (leucine, isoleucine, valine, phenylalanine, and tyrosine). Improvements in pig growth have been observed with Trp:Lys ratios greater than 18%.
  6. 6Ratio is at least 60% when high levels of blood meal or cells are included in the diet. Ratio may be lower than 52% when blood cells are not included, but more research is required to verify and to determine the optimal ratio of isoleucine to leucine.