Effect of poultry droppings on the primary productivity and growth performance of major carps in polyculture system

Effect of broiler droppings has been studied on primary productivity,and net fish yield of major carps for one year in four earthen fish ponds. catla catla,labeo rohlita and cirrhinus mrigala were stocked with a ratio of 40:30:30 to test the input of broiler droppings. based on its nitrogen contents (4.62%) broiler excreta was applied at a rate of 0.15 g nitrogen / 100 g of fish weight daily. the input of this nitrogen source significantly increased the fish weight,fork and total length. statistically the differences were non-significant between labeo rohita and cirrhinus mrigala for an increase in their body weight. the plankton productivity,phyto- and zooplankton abundance and phytoplankton/ zooplankton ratios were significantly different in treated and control ponds. increase in fish yield and nitrogen incorporation efficiency of fish was found to be correlated with water temperature and plankton productivity in treated and control ponds. the plankton biomass was found to depend on the water temperature. the net fish yield of 3951.42 and 828.64 kg/ha/year of major carps were secured from broiler manure treated and control ponds,respectively. the suitable environment in a manured pond resulted in a significantly better growth of major carps than the control pond. in the absence of any harmful effects of ammonia on the survival of fish,the fish yields can be quite easily enhanced with an application of broiler manure at low or no cost. copyright © 2014 zoological society of pakistan.