1995 and 1996 80:20 POND FIELD TRIALS WITH CRUCIAN CARP, PACU, TILAPIA AND WUCHANG CARP
Fourteen pond trials were conducted in 1995 and 1996 to assess the fingerling to market growth of crucian carp, pacu, tilapia and wuchang carp (bream) with a variety of aquafeed formulations. The objective of the trials was to test and demonstrate the technical and economic feasibility of production of these species in 80:20 culture systems with feeds formulated primarily from plant proteins. An all-plant protein diet (‘J’) was tested against similar diets (‘H’ and ‘K’) containing primarily plant protein and 5% fish meal.
The all-plant protein ‘J’ diet produced as good or better growth than the ‘H’ diet containing fish meal with crucian carp. Crucian carp of approximately 50 g grew to an average of 227 g in six trials. The production target of 250 g was reached in only two trials. Float and sink forms of the test diets produced inconsistent results. Observations indicate crucian carp are not aggressive feeders and may require training at the fry to fingerling stage to readily adapt to floating feeds. Economic return with crucian carp was highly variable.
Pacu reached the production target of >400 g in two trials conducted and with all three diets tested (‘H’, ‘J’ and ‘K’). There was no difference in pacu growth among the test diets, or among floating and sinking forms of the ‘H’ diet. Feed conversion ratios of 1.2-1.6 indicated rapid and economical growth of pacu on all diets.
Nile tilapia growth was best on the ‘K’ diet, although tilapia grew rapidly on both the ‘J’ and ‘K’ diets tested in one trial in 1995. Average daily growth rates were 8.3% and 9.7% of body weight, respectively, with 31-g fingerlings growing to 355-410 g in 126 days. A 1996 trial stocked fingerlings of 6 g that were unable to attain market size by the end of the production season. There was no growth difference of fingerlings with the ‘J’ and ‘H’ feeds.
Bream growth was also better on the ‘K’ diet, with only minor variations in growth among the ‘H’ and ‘J’ diets in three trials. Floating feeds produced better growth than sinking feeds with bream. Average bream growth, feed conversion ratio and economic return with the three diets was 356 g, 1.8 and Y3255/mu.