then supplied to experimental tanks at a flow rate of approximately 600 mlrmin. Effluent water drained from experimental tanks via standpipes and 20–25 of this water
was discarded. The rest was collected in a common sump and recirculated through a 2000-l biological filter for re-use in the laboratory. Each digestibility tank contained two
air stone diffusers. During all experiments, dissolved oxygen was maintained above 5.0 mgrl, pH between 7.2 and 8.5 and water temperature between 23.28C and 28.08C.
Ž .
Ž .
Nitrite NO –N and ammonia total ammonia–N was measured weekly following
2
Ž .
methods described in Allan et al. 1990 , and levels did not exceed 0.2 and 0.3 mgrl, respectively.
2.5. Chemical analyses All chemical analyses of feed and faecal samples were done in duplicate. Dry matter,
Ž .
ash and energy bomb calorimetry were determined using procedures described in Ž
. AOAC 1990 . Nitrogen was determined using Kjeldahl or semi-micro Kjeldahl methods
Ž .
AOAC, 1990 and crude protein content estimated by multiplying nitrogen by 6.25. Ž
. Chromic oxide was determined by the method described in Scott 1978 . Amino acids
were analysed following acid hydrolysis using high pressure liquid chromatography and Ž
. Waters Pico-Tag Waters, Lane Cove, NSW, Australia . Sulphur amino acids were
determined separately following performic acid digestion, and tryptophan, which is lost Ž
. during acid hydrolysis, was not determined Cohen et al., 1989 .
2.6. Digestibility determinations Ž
. Apparent digestibility coefficients
ADCs for dry matter, energy, nitrogen and
availability of amino acids for the reference and test diets were calculated by the Ž .
w Ž
.x formula, ADC s 100 = 1 y FrD = DC rFC
where F is the percent of nutrient
r r
or energy in faeces, D is the percent of nutrient or energy in diet, DC is the percent of
r
Ž chromic oxide in diet and FC
is the percent of chromic oxide in faeces Cho and
r
. Ž
. Kaushik, 1990 . Then, ADCs availability for ingredients were determined after the
individual contribution of nutrients or energy from the reference diet and test ingredients Ž .
Ž were considered. The following formula was applied: AD
s Nutr =
AD y
ING TD
TD
. Ž .
0.69 = Nutr =
AD r 0.29 = Nutr
, where AD is apparent digestibility
RD RD
ING ING
Ž .
availability of nutrient or energy in the test ingredient, Nutr is the nutrient or energy
TD
Ž .
concentration in test diet, AD is the apparent digestibility availability of the nutrient
TD
or energy in the test diet, Nutr is the nutrient or energy concentration in the reference
RD
Ž .
diet, AD is the apparent digestibility availability of nutrient or energy in the
RD
reference diet and Nutr is the nutrient or energy concentration in the test ingredient
ING
Ž .
Sugiura et al., 1998 .
3. Results
Ž .
Composition of ingredients are tabulated Tables 2 and 3 . Except for the high protein glutens from wheat and corn, fish meals and other animal meals were generally higher in
crude protein than oilseeds, legumes or cereals. Lysine was highest in blood meal and fish meals, followed by some of the other terrestrial animal meals, oilseeds, legumes and
cereals. Gross energy value for all ingredients ranged from 16.1, for meat and bone Ž
. meals beef , to 24.9 MJrkg, for feather meal.
Digestibility coefficients for dry matter, protein and energy and availability coeffi- Ž
. cients for amino acids are tabulated Tables 4 and 5 . Occasionally, values over 100
Table 4 Ž
. Mean percent SEM, ns 3 apparent digestibility coefficients for dry matter, nitrogen and gross energy of
the test ingredients using juvenile silver perch and the settlement method of faeces collection Ž .
Test ingredient Apparent digestibility
Dry matter Nitrogen
Energy Fish meals
a
1. Australian fish meal 78.92.2
92.30.4 89.62.2
2. Danish fish meal 93.91.1
94.20.8 98.00.5
3. Peruvian fish meal 76.8q0.2
89.01.6 88.60.6
Animal meals Ž
. 4. Blood meal spray dried
109.01.0 90.20.7
99.91.0 Ž
. 5. Meat and bone meal beef
50.13.3 71.51.8
75.21.5 Ž
. 6. Meat and bone meal lamb
55.40.5 73.90.2
80.80.8 7. Poultry meal
86.21.7 85.41.7
93.71.4 Ž
. 8. Feather meal hydrolysed, ring dried
105.31.0 92.80.7
101.00.5 Oilseeds
Ž .
9. Soybean meal solvent 75.42.0
94.80.6 78.01.6
Ž .
10. Soybean meal whole, expeller 83.80.3
95.70.1 84.10.3
Ž .
11. Soybean meal dehulled, full-fat 77.22.9
92.31.7 79.82.0
Ž .
12. Canola meal solvent 51.93.5
83.01.2 58.12.7
Ž .
13. Canola whole, expeller 47.34.7
79.63.0 58.62.6
14. Peanut meal 74.25.0
98.26.0 77.03.5
Ž .
15. Cottonseed meal dehulled 50.54.3
83.01.0 53.13.0
Ž .
16. Linola linseed meal 30.44.0
77.71.2 44.32.8
Legumes whole Ž
. 17. Lupins-L. angustifolius gungurra
52.43.0 97.10.9
51.21.0 18. Lupins-L. albus
66.80.4 95.90.9
70.11.6 Ž
. 19. Field pea P. satiÕum dunn
51.02.2 81.00.4
51.02.3 Ž
. 20. Faba bean V. faba fijord
58.00.3 90.50.7
59.20.4 Ž
. 21. Chick pea C. arietinum desi
50.80.8 82.21.7
54.80.7 Ž
. 22. Vetch V. satiÕa blanch flur
43.53.2 71.23.0
52.81.0 23. Cow peas Vig. unguiculata
42.68.5 96.51.4
44.75.9 Cereals
24. Wheat gluten 90.62.0
99.80.7 94.01.1
25. Corn gluten meal 113.40.7
95.40.7 104.50.3
Ž .
26. Wheat 1 Aust. Std. Wheat 52.91.8
99.51.7 53.21.2
Ž .
27. Wheat 2 high protein 36.04.3
106.11.0 31.03.6
28. Millrun 53.33.6
86.20.5 55.23.1
29. Sorghum 36.40.9
77.80.6 37.80.7
a
See Table 2.
G.L. Allan
et al.
r Aquaculture
186 2000
293 –
310 302
Table 5 Ž
. Mean percent SEM in italics, ns 3 apparent availability coefficients of amino acids in test ingredients as fed to juvenile silver perch using the settlement method
of faeces collection Ž .
Test ingredient Apparent availability
Lys Met
Cys Thr
Arg Gly
Ser His
Ile Leu
Phe Tyr
Val Pro
Ala Glu
Asp Fish meals
a
1. Australian fish meal 97.1
96.0 98.9
96.1 95.7
88.1 93.9
97.7 96.5 97.2
96.4 95.5
96.2 87.8
92.9 97.0
97.2 0.0
0.3 1.5
0.3 0.4
1.2 0.3
0.6 0.3
0.4 0.4
0.1 0.3
0.7 0.7
0.3 0.2
2. Danish fish meal 97.3
97.8 101.0
96.8 98.0
96.6 95.6
97.8 96.3 97.2
96.2 94.3
97.0 94.1
97.1 98.1
97.3 0.2
0.4 0.9
0.2 0.2
0.2 1.0
0.3 0.1
0.3 0.0
0.6 0.1
0.7 0.2
0.2 0.8
3. Peruvian fish meal 95.2
91.2 88.7
92.9 91.3
82.3 90.7
95.6 93.3 93.8
91.8 92.9
92.9 81.2
89.6 94.2
94.3 0.5
1.0 1.1
0.5 0.5
1.0 1.0
0.6 0.5
0.5 0.7
0.6 0.5
0.3 0.5
0.4 0.5
Animal meals Ž
. 4. Blood meal spray dried
92.9 91.6
87.0 93.8
93.3 92.8
94.3 94.4
80.0 92.9 92.9
93.1 92.2
92.8 93.2
93.6 94.1
0.7 1.2
1.2 0.7
0.8 1.0
0.7 0.6
3.5 0.7
0.9 0.9
0.7 1.0
0.8 0.9
0.7 Ž
. 5. Meat and bone meal beef
75.8 81.8
67.5 76.4
73.5 67.0
75.1 75.8
74.8 78.0 74.7
80.9 74.4
69.5 70.0
75.0 76.2
1.0 1.1
8.0 0.7
0.7 1.4
0.3 0.4
0.9 0.5
1.1 0.6
0.5 1.1
1.3 0.5
0.9 Ž
. 6. Meat and bone meal lamb
84.6 84.4
82.3 83.8
77.3 65.6
79.6 89.5
85.6 85.8 83.7
87.0 83.3
68.1 73.8
83.4 86.8
0.9 1.4
7.5 0.4
1.2 1.5
1.2 0.2
1.0 0.8
0.9 0.4
1.2 1.6
1.5 0.8
0.7 7. Poultry meal
89.3 92.1
90.5 87.8
88.5 83.4
86.3 90.7
85.0 86.9 85.5
86.2 84.5
83.3 85.0
88.4 86.0
1.7 1.1
1.8 1.8
1.0 1.3
2.0 1.8
2.0 1.9
1.8 1.7
1.9 1.3
1.3 1.8
2.3 Ž
. 8. Feather meal hydrolysed, ring dried
89.6 96.3
91.6 92.8
96.1 94.5
94.7 92.9
93.5 93.7 94.4
91.4 92.8
93.7 93.6
93.3 90.4
1.1 0.2
0.1 0.4
0.4 0.6
0.4 1.1
0.6 0.5
0.5 0.7
0.5 0.5
0.7 0.6
0.6 Oilseeds
Ž .
9. Soybean meal solvent 96.7
95.7 94.1
95.5 97.8
94.4 95.3
96.7 94.9 94.8
95.6 96.2
94.8 96.8
94.6 96.9
95.9 0.5
2.0 0.8
0.5 0.6
1.4 0.5
0.7 0.6
0.8 0.6
0.8 0.8
1.1 1.3
0.5 0.1
Ž .
10. Soybean meal whole, expeller 96.9
98.1 94.0
95.5 97.6
92.5 95.3
96.8 96.9 96.4
97.3 96.4
96.5 96.8
94.0 96.6
95.7 0.4
0.3 0.6
0.4 0.2
0.8 0.4
0.3 0.5
0.5 0.2
0.7 0.5
0.8 0.5
0.1 0.4
G.L. Allan
et al.
r Aquaculture
186 2000
293 –
310
303 Ž
. 11. Soybean meal dehulled, full-fat
94.5 95.7
96.5 94.0
95.4 88.5
93.7 94.2
92.0 92.2 93.1
93.6 91.2
94.7 91.4
94.5 92.3
0.9 1.8
1.5 0.6
0.7 2.5
0.7 0.7
0.7 0.8
0.8 0.6
1.1 1.7
1.4 0.4
0.5 Ž
. 12. Canola meal solvent
86.2 89.2
79.8 87.9
91.7 85.0
85.9 91.7
84.6 87.8 88.0
89.8 84.6
84.8 86.0
91.4 82.5
0.7 1.5
3.5 0.6
0.7 2.0
1.3 1.0
1.0 1.2
1.0 0.8
1.1 1.2
1.7 0.9
1.9 Ž
. 13. Canola meal whole, expeller
85.5 85.2
79.8 85.5
91.2 82.0
81.9 90.3
84.5 86.1 87.3
86.6 84.9
82.0 83.7
90.6 82.0
1.8 3.9
3.4 1.5
1.6 3.7
2.1 1.1
2.4 2.2
2.3 2.3
2.1 2.9
3.3 1.1
2.0 14. Peanut meal
89.5 97.8
97.5 90.3
96.3 85.8
91.7 94.7
91.9 92.3 94.1
96.7 92.5
90.8 91.9
95.2 94.7
2.7 2.6
2.6 2.3
0.8 3.3
1.6 1.6
2.1 2.0
1.6 3.4
1.9 4.8
2.3 0.9
0.8 Ž
. 15. Cottonseed meal dehulled
60.4 74.4
79.3 77.7
91.3 77.1
81.0 87.4
74.3 75.1 82.5
82.8 76.8
82.7 75.5
88.6 84.7
0.6 5.3
2.6 1.1
0.4 1.6
1.9 2.0
1.5 1.1
0.9 1.0
1.5 1.8
1.2 0.7
1.9 Ž
. 16. Linola linseed meal
80.6 89.1
74.2 78.8
91.6 74.2
81.3 79.5
84.6 80.9 85.5
83.3 82.6
72.3 78.6
86.9 79.8
1.4 0.9
1.9 1.7
0.9 1.6
1.1 1.5
1.3 0.8
1.4 1.4
1.5 1.7
1.7 0.7
1.0 Legumes
Ž .
17. Lupin-L. angustifolius gungurra 99.7
87.4 79.5
98.3 99.3
107.4 93.0
102.2 96.7 96.6
97.8 96.1
97.0 98.5
102.5 95.8
90.0 2.1
23.1 2.0
2.1 0.9
3.5 2.5
2.8 2.3
2.5 2.7
2.5 2.7
4.4 2.8
1.4 2.1
18. Lupin-L. albus 99.2
102.2 84.8
97.9 99.3
107.8 94.3
100.3 94.9 95.7
96.3 95.4
95.5 99.5
102.5 96.2
93.3 0.5
4.5 4.4
0.5 0.5
2.7 0.9
2.3 1.0
1.0 1.0
0.4 1.5
1.6 1.9
1.0 1.1
Ž .
19. Field pea P. satiÕum dunn 86.1
67.8 60.8
74.5 88.9
69.2 72.8
79.2 78.0 78.8
79.8 78.5
75.9 70.6
76.8 84.7
81.8 1.3
5.6 1.4
1.8 1.0
1.5 0.8
3.3 2.4
2.4 1.7
1.0 1.8
0.2 1.8
0.7 1.3
Ž .
20. Faba bean V. faba fijord 88.7
81.9 81.5
82.3 93.5
78.3 85.0
86.9 83.1 87.4
85.4 83.3
82.9 84.6
83.6 88.7
84.5 0.4
2.2 0.7
1.8 0.9
0.4 0.7
2.4 1.2
2.8 1.0
0.8 1.0
0.5 1.6
0.5 0.4
Ž .
21. Chick pea C. arietinum desi 76.1
75.4 64.1
57.6 80.6
56.9 65.3
73.3 60.8 65.8
66.0 61.8
58.4 60.4
59.3 71.9
66.5 1.0
2.6 3.4
2.0 0.7
2.5 1.2
1.8 1.5
1.2 1.3
2.1 1.5
1.6 1.4
0.6 0.9
Ž .
22. Vetch V. satiÕa blanch flur 64.9
42.0 48.4
42.1 75.9
51.8 53.3
63.2 58.4 60.1
50.2 52.0
56.0 50.4
53.8 69.6
66.9 1.8
2.6 10.3
1.2 0.4
1.6 1.7
1.2 1.0
0.6 1.1
1.3 0.5
1.2 1.8
0.2 1.4
23. Cow peas Vig. unguiculata 76.3
83.8 86.6
78.9 85.2
65.1 85.1
85.7 73.7 76.9
73.0 70.6
75.8 90.4
76.8 83.3
83.7 1.6
1.9 5.0
1.5 1.2
3.6 1.5
1.9 2.3
1.8 2.2
2.8 1.8
1.6 2.1
1.0 1.3
Ž continued on next page
G.L. Allan
et al.
r Aquaculture
186 2000
293 –
310 304
Ž Table 5 continued
Ž . Test ingredient
Apparent availability Lys
Met Cys
Thr Arg
Gly Ser
His Ile
Leu Phe
Tyr Val
Pro Ala
Glu Asp
Cereals 24. Wheat gluten
100.5 102.9
101.9 100.2
100.6 99.3
100.1 100.9
100.6 101.0
100.7 99.3
100.5 99.6
100.1 99.8
99.8 0.6
0.8 0.1
0.2 0.2
0.5 0.0
0.1 0.2
0.2 0.0
0.3 0.3
0.3 0.6
0.1 0.6
25. Corn gluten meal 87.9
94.0 90.6
94.3 97.1
92.4 96.2
94.4 94.7
97.9 97.7
96.9 95.1
97.6 97.5
98.1 94.9
1.7 0.7
0.9 0.4
0.5 1.3
0.3 0.5
0.8 0.3
0.4 0.2
0.6 0.3
0.4 0.3
0.6 Ž
. 26. Wheat 1 Aust. Std. Wheat
98.7 110.2
91.1 94.3
95.4 83.1
97.5 99.0
99.5 102.4
100.0 94.6
93.2 97.9
84.7 95.4
61.2 1.9
2.0 4.4
2.7 2.0
2.0 3.1
3.1 1.8
2.5 1.9
1.6 3.2
0.8 2.6
0.8 1.8
Ž .
27. Wheat 2 high protein 111.8
119.1 90.0
79.6 106.9
114.7 102.1
99.7 108.8
104.2 104.4
95.8 101.4
104.6 104.2
97.2 53.3
3.2 1.7
3.2 2.5
2.1 2.8
1.0 1.8
2.0 1.3
2.0 1.0
1.6 1.0
2.9 0.6
1.5 28. Millrun
87.7 90.0
78.6 82.8
91.8 87.5
87.3 90.2
85.5 84.3
87.2 81.9
84.2 92.3
86.2 92.9
84.6 2.1
3.2 1.0
2.2 1.5
1.2 1.4
3.8 2.7
2.0 1.8
2.4 1.9
0.8 1.1
1.0 2.0
29. Sorghum 74.5
71.7 57.1
72.6 83.2
73.7 80.1
82.4 81.9
86.4 86.4
79.3 79.4
84.9 84.7
88.2 76.4
5.5 5.9
9.0 6.8
5.0 8.0
4.8 2.6
3.6 1.9
2.2 3.8
3.7 2.5
2.8 2.2
6.1
a
See Table 2.
were recorded. This may have been due to minor errors in measurement, which are compounded in calculations used to estimate digestibility coefficients, possible interac-
tions between nutrients in the reference diet and test ingredients or differential leaching of some nutrients within ingredients. The exact values calculated are presented here
although it should be noted that values 100 were rounded off to 100 for subsequent least-cost diet formulation. For dry matter, digestibility values exceeding
75 were recorded for fish meals, blood meal, poultry products, soybean and gluten from wheat and corn. Values for all other ingredients were above 50 except for
Ž .
Ž .
Ž .
Ž .
expeller canola 47.3 , linola 30.4 , vetch 43.5 , high protein wheat 36 and Ž
. sorghum 36.4 . Protein was generally well digested in most ingredients with only
Ž .
meat meal and bone meal from lamb and beef , expeller canola, linola and vetch yielding protein digestibility coefficients below 80.
Dry matter digestibility coefficients were reliable indicators for energy digestibility for all ingredients, except for meat meal and bone meals, which had low dry matter
Ž .
Ž .
digestibility due to high ash content but high energy digestibility, and canola expeller , Ž
linola and vetch, which also had low dry matter digestibility due to poor protein .
digestibility but high energy digestibility. In general, amino acid availability reflected crude protein digestibility; however, for
some ingredients, there were some major differences in availability of different amino acids. For the fish meals, Peruvian fish meal had lower availability of glycine and
proline compared with the availability of the other amino acids. Availability of amino acids for the other fish meals were similar. For the animal meals, amino acid availability
was quite different for blood meal and the two meat and bone meals, but similar for the poultry ingredients. Isoleucine availability was relatively low for blood meal while
glycine, proline and cystine were low for meat and bone meal. Among the oilseeds,
Ž .
differences in availability were evident for canola cystine was lowest , cottonseed meal Ž
. Ž
. lysine was lowest and linola proline was lowest . For the legumes, cystine availability
was relatively low for lupins and field peas, glycine for faba beans, while chick peas and cow peas had several amino acids, which were less available. Among the cereals,
availability of amino acids were similar, except for sorghum where cystine was less available than the other amino acids.
4. Discussion
