Nutrient Requirements of Broilers a

Ageb

0–3 weeks

3–6 weeks

6–8 weeks

kcal AMEn/kg dietc

3,200

3,200

3,200

Crude proteind

23.00

20.00

18.00

Arginine

1.25

1.10

1.00

Glycine + serine

1.25

1.14

0.97

Histidine

0.35

0.32

0.27

Isoleucine

0.80

0.73

0.62

Leucine

1.20

1.09

0.93

Lysinee

1.10

1.00

0.85

Methionine

0.50

0.38

0.32

Methionine + cystine

0.90

0.72

0.60

Phenylalanine

0.72

0.65

0.56

Phenylalanine + tyrosine

1.34

1.22

1.04

Proline

0.60

0.55

0.46

Threonine

0.80

0.74

0.68

Tryptophan

0.20

0.18

0.16

Valine

0.90

0.82

0.70

a Requirements are listed as percentages of diet.

b The 0- to 3-, 3- to 6-, and 6- to 8-week intervals for nutrient requirements are based on chronology for which research data were available; however, these nutrient requirements are often implemented at younger age intervals or on a weight-of-feed consumed basis.

c These are typical dietary energy concentrations. Different energy values may be appropriate depending on local ingredient prices and availability.

d Broiler chickens do not have a requirement for crude protein per se. However, there should be sufficient crude protein to ensure an adequate nitrogen supply for synthesis of nonessential amino acids. Suggested requirements for crude protein are typical of those derived with corn-soybean meal diets, and levels can be reduced when synthetic amino acids are used.

e Recent research has shown that higher levels of lysine are needed for maximal growth and efficiency of modern broilers.

Adapted, with permission, from Nutrient Requirements of Poultry, 1994, National Academy of Sciences, National Academy Press, Washington, DC.