1995 and 1996 LVHD CAGE FIELD TRIALS WITH NILE TILAPIA, COMMON CARP, CRUCIAN CARP, WUCHANG CARP AND CHANNEL CATFISH
Region: Northeast AsiaDownload
Twenty-three cage trials were conducted in 1995 and 1996 to assess fry-fingerling and fingerling-market production potential of Nile tilapia, common carp, crucian carp, wuchang carp (bream), and channel catfish in low-volume high-density (LVHD) cages. The objective of the trials was to test and demonstrate the technical and economic feasibility of production of these species in LVHD cage culture systems with feeds formulated primarily from plant proteins. An all-plant protein diet was tested against similar diets containing 5-10% fish meal.
The all-plant protein ‘J’ diet produced as good or better growth than the ‘H’ and ‘K’ diets containing 5% fish meal in 6 of 8 comparison trials with nile tilapia, 5 of 7 trials with common carp, and all trials with crucian carp and bream. Nile tilapia averaged daily weight gains of 5.4% and 3.1% per day for 50 g and >96 g fingerlings, respectively. Average net income was Y335/m3 ($40.55/m3) for all Nile tilapia trials reporting economic data. Highest net income was Y562/m3 ($68.04/m3) with the ‘J’ floating feed. Nile tilapia fry to fingerling production inLVHD cages was technically and economically feasible, with average net economic returns of Y360/m3 ($43.58/m3).
Common carp did not demonstrate a requirement for fishmeal in formulated feeds. Fish in seven cage trials gained an average of 2.6% of body weight per day on all diets tested. Best comparative growth performance was with the ‘H’ and ‘J’ feeds. The ‘H’ feed produced 7-13% better growth than the ‘K’ feed in two comparison trials. There were no differences in growthwith the ‘K’ and ‘S’ feeds in one comparative trial. Stocking density had no effect on common carp growth. Fish at 400-500/m3 grew at an average rate of 2.65% of body weight per day, while fish at 270-300/m3 grew at an average rate of 2.5% of body weight per day.
Crucian carp fingerlings of 20-26 g did not attain a target market size of 250 g in two cage production trials. Maximum growth with 26-g fingerlings was 177 g with the ‘J’ feed. Stocking of larger fingerlings is indicated to reach market size by the end of the production season. Average FCR of 2.45 was high and indicates a need to modify feed formulations for crucian carp in cages.
Bream did not demonstrate a requirement for fishmeal in one LVHD trial conducted. Floating forms of the ‘H’ and ‘J’ feeds produced 6.7% better growth than the sinking forms of the feedsat the 330/m3 density tested. Fingerling stocking size of 35 g was too small to produce market size fish in this trial.