Agriculture Reference
In-Depth Information
Table 17.6.
Fitted equations describing responses to methionine + cysteine, body weight gain (BWG,
g/day), feed conversion ratio (FCR, g/g), body protein deposition (BPd, g/day) and body lipid content (BLc,
g/kg) at optimum intake, and optimum intakes (Met+Cysi,
i
, mg/day) and contents (Met+Cys
i
, g/kg) of
methionine + cysteine when fed to broiler males and females in starter, grower and finisher phases.
Optimum
response
Equation
Met+Cys
i
Met+Cys
i
Starter phase
Females
BPd = -0.00006 × Met+Cys
i
2
+ 0.04 × Met+Cys
i
- 5.28
4.75
268
8.65
BLc = 0.0004 + Met+Cys
i
2
- 0.68 × Met+Cys
i
+ 161.49
57.7
279
9.00
Males
BPd = -0.00007 × Met+Cys
i
2
+ 0.04 × Met+Cys
i
- 5.26
4.78
245
7.21
BLc = 0.001 × Met+Cys
i
2
- 0.92 × Met+Cys
i
+ 183.33
31.5
344
10.1
Combined
BWG = -0.0005 × Met+Cys
i
2
+ 0.25 × Met+Cys
i
- 31.39
28.9
224
6.79
FCR = 0.00002 × Met+Cys
i
2
- 0.01 × Met+Cys
i
+ 1.57
1.20
231
7.00
Grower phase
Females
BWG = -0.0002 × Met+Cys
i
2
+ 0.23 × Met+Cys
i
- 62.53
56.4
486
4.54
BPd = -0.00002 × Met+Cys
i
2
+ 0.03 × Met+Cys
i
- 9.77
9.97
510
4.77
BLc = 0.0002 × Met+Cys
i
2
- 0.45 × Met+Cys
i
+ 204.07
61.0
620
5.79
Males
BWG = -0.0002 × Met+Cys
i
2
+ 0.23 × Met+Cys
i
- 71.314
63.2
543
4.68
BPd = -0.00002 × Met+Cys
i
2
+ 0.03 × Met+Cys
i
- 11.32
10.4
564
4.86
BLc = 0.0002 × Met+Cys
i
2
- 0.45 × Met+Cys
i
+ 218.28
39.8
810
6.98
Combined
FCR = 0.000008 × Met+Cys
i
2
- 0.01 × Met+Cys
i
+ 3.04
1.40
524
4.68
Finisher phase
Females
BWG = -0.00008 × Met+Cys
i
2
+ 0.17 × Met+Cys
i
- 80.51
86.7
853
4.87
FCR = 0.000003 × Met+Cys
i
2
- 0.006 × Met+Cys
i
+ 3.18
1.87
923
5.27
BPd = -0.00002 × Met+Cys
i
2
+ 0.03 × Met+Cys
i
- 16.13
15.0
822
4.70
BLc = 0.0001 × Met+Cys
i
2
- 0.33 × Met+Cys
i
+ 188.29
132
986
5.63
Males
BWG = -0.00008 × Met+Cys
i
2
+ 0.18 × Met+Cys
i
- 107.69
104
1033
5.30
FCR = 0.000003 × Met+Cys
i
2
- 0.006 × Met+Cys
i
+ 3.83
1.80
1053
5.40
BPd = -0.00001 × Met+Cys
i
2
+ 0.04 × Met+Cys
i
- 21.31
17.9
1063
5.45
BLc = 0.0001 × Met+Cys
i
2
- 0.38 × Met+Cys
i
+ 250.15
90.0
1161
5.95
a
mg/bird/day.
b
g/kg.
was measured and their intakes required to
maximize performance was estimated.
The diet formulation technique directly
affects the responses of animals to amino
acid intake. Gous and Morris (1985) favou-
dose-response experiments involving indi-
vidual amino acids, since it favours the ex-
pression of the productive potential of the
poultry. According to Gous (1980), when this
technique is used the balance of amino acids
