Effect of feed, manure and their combination on the growth of Cyprinus carpio (L.) fry and fingerlings

Abstract

Two field experiments, each of 120-day, were conducted in twelve earthen ponds, each with dimensions 50 x 20 x 1.0m (length x width x depth) were located at Serow Fish Farm, National Institute of Oceanography And Fisheries, Dakahlia Governorate, Egypt, with a view to study the effect of nutrient inputs (feed, manure and their combination) on the common carp (Cyprinus carpio) fry and fingerlings of the fish. The treatments consisted of control (C, T1), only feed (F, T2), only manure (M, T3) and manure plus feed (M+F (T4)). Poultry manure was applied in split doses to ponds of manure treatments (M and M+F). Fry (Experiment one) and fingerlings (Experiment two) of average initial weight 0.67 g and 3.2 g respectively, were stocked seven days after the initial manure application at 5 individuals/m2. Fish in F and M+F treatments were provided a fish meal based pelleted diet once daily in the morning at 5% of body weight. The most dominant genera of phytoplankton encountered were Microcystis, Anabaena and Microspora, while among the zooplankton, Keratella and Nauplii dominated. M+F treatment had the highest plankton biomass (P<0.05). Significant (P<0.05) variation in both phyto and zooplankton dry weight was recorded with respect to the study period. Both feeding and manuring, individually and in combination, significantly improved (P<0.05) the growth of the fish. The highest specific growth rate, final fish weight, and gross production were recorded in M+F treatment in both the experiments. The difference in survival among the control and treatments was not significant in experiment one (P>0.05), whereas F and M+F treatments recorded lower survival (P<0.05) in the second experiment. Fish production was comparable under feed (F) and manure (M) treatments (P>0.05) in experiment one, but was significantly (P<0.05) different in experiment two. The increment in gross fish production over the control was 103.22 and 119.99% in feed, 77.30 and 59.44% in manure and 162.34 and 175.08% in M+F treatments of the two experiments respectively. Carcass protein, fat and ash contents were significantly (P<0.05) higher in the three treatments as compared to the control.

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“…One of the major reasons causing chronic stress in farmed fish is stocking high density of fish in a given area to produce maximum commercial output (Iguchi, Ogawa, Nagae, & Ito, 2003;Hussein, 2012). High stocking density has been considered as aquaculture related chronic stressor which causes growth suppression (Barton, 1991;Barton & Iwama, 1991;Wedemeyer, 1997).…”