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Pond and tank feeding trials with carp, Cyprinus carpio L.: gross nutrition, conversion efficiency and cost‐effective diets
Author(s) -
O'GRADY K. T.,
SPILLETT P. B.
Publication year - 1987
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.1987.tb00126.x
Subject(s) - biology , feed conversion ratio , cyprinus , zoology , protein efficiency ratio , carp , trout , common carp , fishery , food science , body weight , fish <actinopterygii> , endocrinology
. Carp feeding trials were conducted to assess dietary effectiveness in relation to growth rate, cost, conversion ratio, logistics and the contribution of natural pond foods. Overall, trout pellets containing 40% protein were found to be the most effective. In laboratory trials this diet fed at 5% bwd −1 produced a food conversion ratio (FCR) of 1·99. Another trout food containing 47% protein, fed at the same ration, had a superior FCR and specific growth rate (SGR) but proved more costly because of a poorer protein efficiency ratio (PER). Optimum ration size declined with increasing body size. The mammalian herbivore diets, with higher carbohydrate but low lipid levels, were cheaper to purchase but had poorer SGRs and FCRs. Some evidence of protein sparing occurred with low levels of activated sludge substitution but condition and growth rate declined above the 20% substitution level probably due to increasing heavy metal concentrations. In the pond trials extensive production levels of 300–350 kg ha −1 year −1 arose from zooplankton consumption. The associated SGR was around 1·70 and the FCR was calculated at 1·64 (dw) assuming 47% utilization of the zooplankton. Higher levels of production (1400–2200 kg ha −1 year −1 ) occurred with supplementary feeding with SGRs at 1·78–2·35. The contribution of natural food was slight in intensive rearing. An FCR of 2·01 was found with trout pellets and an estimated 6·3 with barley.