[Digestion, growth and body composition of carp (Cyprinus carpio L.) after feeding different starch varieties]

Maize starch (treatment I), pregelatinized maize starch (II), wheat starch (III), pregelatinized wheat starch (IV), potato starch (V) or manioc meal (VI) were mixed in portions of 41% (I-V) or 46.7% (VI) to a basal diet. Each experimental diet was fed to 33 carp (Cyprinus carpio L.) (three aquaria with 11 carp each) in a daily amount of 1.8-2.0% of live weight. The experiment lasted 118 days and the carp had a mean live weight of 146 g at the beginning. The diets I-IV had a similar, high energy digestibility of about 90%, whereas the diet with potato starch and the diet with manioc meal significantly lowered the digestibility of the energy to 85% or 87%. The growth and the feed expenditure were not influenced by the different starches. The carp had a mean final weight of 520 g. All carcasses had, on average, a content of ash, protein, fat and energy of 2.8%, 15.7%, 9.4% and 7.4 kJ per g fresh matter. However, potato starch and manioc meal distinctly reduced the energy retention in comparison to maize and wheat starch (diet I or III) because the contents of dry matter, fat and energy of the carcasses of these carp were significantly lowered.