REPLACEMENT OF SOYBEAN WITH RAW AND PROCESSED DUCKWEED AFFECT THE PERFORMANCE AND HAEMATOLOGICAL INDICES OF NILE TILAPIA

Abstract

This research investigated the effects of treated duckweed meal (DWM) supplemented diets on growth, nutrients
utilization and haematology of Oreochromis niloticus as soybean substitute. Nile tilapia were fed isonitrogenous
diets (37% crude protein) formulated on protein for protein basis and prepared from differently treated DWM of
raw (Ra), cooked (Co) and soaked in potash (So) by gradual replacement of soybean meal at Control 0; Ra5,
Ra10, Ra15%; Co5, Co10, Co15% and So5, So10, So15% respectively. Juvenile O. niloticus (n=300; 12.0±0.10g;
10fish tank-1) were randomly allocated to triplicate treatments in 3×4×3 factorial experiment. The fish were fed
to satiation twice daily for 84 days. Growth, nutrient utilization and haematological indices were studied. There
were no significant (p>0.05) differences in performance and nutrients utilization indices of MWG, SGR and FCR
amongst the treatments, except NPU (%) and survival (%) which were significantly (p<0.05) highest (85.69±1.38)
in Ra10 and 95.00±3.91 in Control (0%) but lowest (75.75±1.38) in Co10 and 70.00±3.91 in Co10, respectively.
PCV and haemoglobin ranged from 18.00±1.57 (Ra15) to 26.00±1.57 (Co15) and 5.95±0.50 (So10) to 7.95±0.50
(Co15), respectively, were not significantly (p>0.05) different from the control (0%). This Processing method did
not improve the performance of O. niloticus fed duckweed feed efficiently above soybean, which may be due to
other factors in the dietary treatments.