SWINE RESEARCH
REPORT 44
AJINOMOTO ANIMAL NUTRITION
AJINOMOTO HEARTLAND, INC.
Evaluate the lysine and threonine requirements for
late nursery pigs (25-50 lbs)
Introduction
Objective
Amino acid to lysine requirement ratio research is
difficult to conduct. In order for the ratio in question
to be meaningful, lysine must be limiting in the test
diets and the test amino acid needs be relatively
more limiting than lysine. Unless one treatment in
this experiment proves lysine is limiting, the
uncertainty of whether or not lysine was below the
requirement remains. Also, the question can be
asked – whether or not the ratio was biased by
under-feeding lysine?
Evaluate the lysine and threonine requirements for
late nursery pigs (25-50) simultaneously and use
these values to estimate an accurate thr:lys
requirement ratio.
To prevent these uncertainties an experiment can
be designed to simultaneously estimate the
requirement of both lysine and the amino acid in
question. The two appropriate values can then be
combined to determine the requirement ratio. We
believe that this design is the most accurate.
Experimental Design
A total of 360 (Genetiporc) pigs were randomly
allotted to one of nine dietary treatments (Diets 5
and 10 are the same) with 5 pigs/pen and 7
pens/treatment. The first five treatments were
L-Lysine titration with 0.9, 1.0, 1.1, 1.2, and 1.3%
TID Lysine, respectively. The second five diets
were all formulated at 1.3% TID Lysine with TID
Threonine levels corresponding to 0.60, 0.66, 0.73,
0.79 and 0.85%, respectively (Table 1 a+b). In all
diets amino acids other than the one under
investigation were maintained at or above their
requirement. The trial took place over a 17 d
period with pig weights and pen feed intakes
recorded at initiation and conclusion.
Table 1. Diet composition of experimental diets
TID Lys Level
TID Thr Level
1
0.90
0.85
2
1.00
0.85
Corn
SBM, 46.5%
CWG
Monocal
Limestone
Salt
Vitamin Premix
TM premix
Antibiotic
Isoleucine
Valine
Tryptophan
L-Threonine
Lysine HCl
DL-Methionine
Corn Starch
TOTAL
1319
553
30
31
19
7
5
3
10
0
0
0
0
0.37
0
22.63
2000
1319
553
30
31
19
7
5
3
10
0.10
0.38
0.13
1.25
2.91
1.13
17.10
2000
Lysine Trial
3
1.10
0.85
1319
553
30
31
19
7
5
3
10
0.20
0.75
0.25
2.50
5.46
2.25
11.59
2000
4
1.20
0.85
5
1.30
0.85
6
1.30
0.60
Threonine Trial
7
8
1.30
1.30
0.66
0.73
9
1.30
0.79
10
1.30
0.85
1319
553
30
31
19
7
5
3
10
0.30
1.13
0.38
3.75
8
3.38
6.06
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
5.00
10.54
4.50
0.56
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
0.0
10.54
4.5
5.56
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
1.25
10.54
4.5
4.31
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
3.75
10.54
4.5
1.81
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
5.00
10.54
4.5
0.56
2000
1319
553
30
31
19
7
5
3
10
0.4
1.5
0.5
2.50
10.54
4.5
3.06
2000
Table 1b. Nutrient composition of experimental diets
TID Lys Level
TID Thr Level
1
0.90
0.85
2
1.00
0.85
Lysine Trial
3
1.10
0.85
4
1.20
0.85
5
1.30
0.85
6
1.30
0.60
7
1.30
0.66
TID Ile:Lys, %
TID Leu:Lys,%
TID M+C:Lys, %
TID Thr:Lys, %
TID Trp:Lys, %
TID Val:Lys, %
ME, kcal/lb
CP, %
Ca, %
Available P,%
Lys:Cal, g/Mcal
77
163
61
69
21
87
1,522
18.5
0.76
0.40
3.04
70
149
61
68
20
81
1,522
18.5
0.76
0.40
3.34
65
136
60
68
19
75
1,522
18.5
0.76
0.40
3.64
60
126
60
67
18
71
1,522
18.5
0.76
0.40
3.94
56
117
60
67
17
67
1,522
18.5
0.76
0.40
4.24
56
117
60
49
17
67
1,522
18.5
0.76
0.40
4.23
56
117
60
54
17
67
1,522
18.5
0.76
0.40
4.23
Threonine Trial
8
1.30
0.73
56
117
60
58
17
67
1,522
18.5
0.76
0.40
4.23
9
1.30
0.79
10
1.30
0.85
56
117
60
63
17
67
1,522
18.5
0.76
0.40
4.24
56
117
60
67
17
67
1,522
18.5
0.76
0.40
4.24
Results
Increasing TID Threonine also had no effect (P >
0.10) on feed intake (Table 2). However, F/G
improved (linear, P < 0.01; quad, P < 0.04) and
ADG increased (linear, P < 0.02; quad, P < 0.03)
with maximum response at 0.79% TID Threonine
(Table 2).
Increasing the TID Lysine level from 0.90 to 1.3%
resulted in increased (linear, P < 0.01; quad, P <
0.02) ADG and improved (linear, P < 0.01; quad,
P< 0.01) F/G. Both parameters were maximized at
1.2% TID Lysine (Table 2). Feed intake was not
affected (P > 0.10).
ab
Table 2. The Optimal True Ileal Digestible Lysine and Threonine Requirement for Nursery Pigs
% Lysine
AA
Level
0.9
1.0
c
1.1
c
% Threonine
1.2
d
1.3
d
0.60
d
0.66
c
ADG, lb
1.17
1.19
1.30
1.32
1.28
1.24
ADFI, lb
2.02c
1.92d
2.02c
2.04c
1.98cd
2.04
F/G
1.72c
1.61d
1.56e
1.54e
1.54e
1.64c
a
A total of 360 pigs (5 pigs/pen) with an initial average BW of 23.7 lb
b
Treatment diets were fed from d 0 to 17
cdc
Means in the same row with different superscripts differ (P < 0.05)
0.73
c
1.26
1.98
1.57d
Lysine
0.79
cd
1.27
1.98
1.55d
0.85
d
1.33
2.04
1.53d
cd
1.28
1.98
1.54e
Threonine
Lin
Quad
Lin
Quad
<0.01
0.81
<0.01
0.02
1.00
<0.01
0.02
0.45
<0.01
0.03
0.64
0.04
SED
0.041
0.077
0.027
Discussions
This design has the ability to simultaneously
determine the lysine and threonine requirements.
Once the lysine requirement is established,
determination of how to evaluate the threonine
response can be concluded. For instance, if lysine
was still limiting at 1.30% TID Lysine, the threonine
part of the study would be a ratio study, but since
the requirement for lysine appears to be 1.20% TID
lysine, the threonine treatments can be viewed as a
requirement experiment also. In doing so, a
quadratic maximum for both F/G and ADG at the
0.79% TID Threonine level are observed.
Now by combining the two data sets, we have
determined not only the lysine and threonine
requirements but also the Thr: Lys ratio (65.8%)
for optimal performance. This is justifiable since
both experiments were conducted at the same
time, with the same pigs, under the same
environmental conditions.
Furthermore, extraction of the limiting points from
the respective curves (the first four points from
each) and regressing the respective TID level over
the performance parameter (either ADG or F/G)
indicates the level of supplementation needed for
a given performance level (Tables 3-4 and Figures
1-4).
Figure 2. Threonine (24-47 lbs)
1.20
0.80
TID Thr (%)
TID Lys (%)
Figure 1. Lysine (24-47 lbs)
y = 1.6185x - 0.965
1.10
R2 = 0.9064
1.00
0.90
y = 1.9778x - 1.8267
R2 = 0.8586
0.75
0.70
0.65
0.60
1.15
1.20
1.25
1.30
1.35
1.15
1.20
ADG (lb/d)
1.25
1.30
1.35
ADG (lb/d)
Table 3. ADG Regression Analysis
ADG
Lysine*
Threonine**
1.21
0.99
0.57
1.24
1.04
0.63
1.27
1.09
0.69
1.30
1.14
0.74
1.33
1.19
0.80
TID Thr:Lys
57
60
63
65
68
% of Max
91
93
95
98
100
*TID Lysine (%) = 1.6185*ADG (lb/d) – 0.965
**TID Threonine (%) = 1.9778*ADG (lb/d)-1.8267
Figure 4. Threonine (24-47 lbs)
1.20
1.10
y = 69.754x2 - 81.59x + 24.759
R2 = 0.9871
TID Lys (%)
TID Lys (%)
Figure 3. Lysine (24-47 lbs)
1.00
0.90
0.56
0.58
0.60
0.62
0.64
0.66
0.80
0.75
0.70
0.65
0.60
y = 111.83x2 - 136.93x + 42.512
R2 = 0.9905
0.60
0.64
ADG (lb/d)
G:F
Table 4. G:F Regression Analysis
G:F
Lysine*
Threonine**
.625
1.01
0.61
.635
1.07
0.65
.645
1.15
0.72
.655
1.24
0.80
0.62
TID Thr:Lys
60
61
62
65
*TID Lysine (%) = 69.754 * ADG (lb/d)^2 - 81.59*ADG (lb/d) + 24.759
**TID Threonine (%) = 111.83 * ADG (lb/d)^2 – 136.93*ADG (lb/d) + 42.512
% of Max
95
97
98
100
0.66
Conclusion
This study determined that for 25 to 50 pound
(Genetiporc) pigs; the optimum TID Lysine level is
1.2% and a respective ratio of TID Thr:Lys of 6568%.
References
Lenehan, N.A., M.D. Tokach, S.S. Dritz, J.L. Usry,
R.D. Goodband, J.M. Derouchey, J.L. Nelssen, and
C.W. Hastad. 2004. Evaluation of the optimal
true-ileal-digestible
lysine
and
threonine
requirement for nursery pigs. Kansas Swine
Industry Day Report of Progress 940. Pp. 68-77
Lenehan, N.A., M.D. Tokach, S.S. Dritz, R.D.
Goodband, J.L. Nelssen, J.L. Usry, J.M.
DeRouchey, and N.Z. Frantz. 2004. The optimal
true ileal digestible lysine and threonine
requirement for nursery pigs between 10 and 20
kg. J. Anim. Sci. 82(Suppl. 1):293(Abstr.).
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