EFFECT OF FISHMEAL REPLACEMENT WITH CHEESE PROCESSING BY-PRODUCT MEAL ON FISH PELLET QUALITY USING RING DIE PELLETING MACHINE

Abstract

This study was performed to use the cheese processing by-product meal (CPBM) as an alternative source of protein instead of the expensive herring fish meal (HFM) in the practical diet of Nile tilapia fingerlings. Three feed blends containing 30% of protein were formulated with three different percentages of CPBM replacement of 0.0 (HFM=100%), 50 and 100% The ingredients of these blends were pelleted using a ring die pelleting machine at roller clearance of 0.0, 1.5 and 3 mm and different moisture contents of 15, 20 and 25% to investigate the effect of the mentioned operating parameters on machine performance measurements, pellets quality as well as the fish growth performance. The obtained results revealed that ,CPBM percentage of 100% ,roller clearance of 0 mm and moisture content of 15% to achieve the highest values of machine productivity of 62 kg/h, pelleting efficiency of 94.50%, lowest specific energy consumption of 26.70 kW.h/Mg and the lowest cost per mass unit of 2978.00 L.E/Mg, while the highest values of durability(93.50%) and pellets bulk density (940 kg/m3)were recorded at roller clearance of 1.5 mm, CPBM percentage of 100% and moisture content of 15%.The results showed that the complete replacement of HFM by CPBM saved the cost per mass unit with about 822 L.E/Mg. For fish growth performance, results showed that the complete replacement of CPBM fish diets gave no significant (P > 0.05) effect on growth performance compared to fish fed the HFM, also no disparity in growth response of fish, efficiency of feed utilization, survival rate and did not affect fish composition of dry matter, protein, or fat .So, CPBM can be used as a cheap source of protein in Nile tilapia diets instead of HFM .