Processed feed pea and canola meal for blue shrimp diets

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L.E. Cruz-Suarez et al.rAquaculture 196 2001 87–104
3. Results
3.1. Stability of the diets in seawater
Average loss of a dietary dry matter following 1-h immersion was approximately
11% for the diets containing pea meals Ž Table 3 ., except for the whole-extruded pea diet
Ž WEX .. This diet and the reference diets Ž 8 and 9.
showed a better water stability. The
extruded canola diet Ž CEX.
exhibited significantly lower water stability; however crude
protein loss was comparatively low. The WEX diet showed the lowest crude protein loss
while the protein stability of the remaining diets was similar to that of control diet in the
growth trial Ž. 7 . The effects of extrusion on increased starch gelatinization Ž Table 1.
may explain the higher water stability of the diet containing whole-extruded peas.
However, this extrusion effect was not observed for dehulled peas: %DML and CPL
values submitted to factorial ANOVA showed significant probabilities for the rawrextruding
factor Ž Ps0.064 and 0.058, respectively ., but not for the wholerdehulled one
Ž Ps0.112 and 0.254, respectively ..
3.2. Feed intake, growth and surÕiÕal
The growth bioassay results and ANOVA probabilities for the calculated parameters
are presented in Table 4. Highly significant differences Ž P-0.001.
in food intake were
observed. The micronized pea meal diet WMI showed the highest consumption while
both extruded pea meal diets, WEX and DEX showed the lowest intake. The raw pea
Table 3
Proximate analysis and calculated energy content of the experimental diets, and dry matter loss Ž %DML.
and
crude protein loss Ž %CPL.
after 1 h immersion in seawater
1 1 1 1 1 3 3
Diet Moisture Crude Lipid Ash Fiber N.F.E Gross %DML %CPL
1
protein
2
energy
1 WRA 7.5 30.6 9.5 8.7 1.4 42.4 4.3 11.2"0.4 b 19.9"3.0 bc
2 WEX 7.5 29.7 8.9 9.0 2.7 42.3 4.2 9.9"1.0 ab 12.6"1.1 a
3 DRA 7.6 30.5 9.6 8.6 0.9 42.8 4.4 11.3"1.0 bc 17.4"3.1 b
4 DEX 7.3 30.8 9.3 8.6 0.9 43.1 4.4 11.1"0.9 b 18.5"1.9 b
5 WMI 7.0 29.6 9.6 8.6 2.4 42.9 4.3 11.2"1.4 b 18.9"1.8 b
6 CEX 7.2 30.2 9.3 8.8 3.8 40.7 4.2 12.6"0.8 c 17.2"1.4 b
7 Control 6.8 31.2 8.9 8.5 1.5 43.2 4.4 11.1"0.5 b 18.9"0.4 b
growth
8 Reference 6.6 35.8 12.8 11.0 1.5 32.3 4.5 9.6"1.0 a 17.3"0.8 b
pea meal
9 Reference 6.7 29.0 11.8 9.1 1.6 41.9 4.5 9.6"0.7 a 19.1"0.6 b
canola
1 % as fed. NFEsnitrogen free extract, calculated by difference.
2
Proteins5.6 kcalrg, lipids9.5 kcalrg, carbohydratess4.1 kcalrg Ž Tacon, 1987 ..
3 Different letters in same column indicate different homogeneous subsets as determined by Duncan’s
multiple comparisons Ž P s0.05 .. One-way ANOVA probabilities were P s0.001 and P s0.006 for DML
and CPL data, respectively.