PARTIAL AND COMPLETE REPLACEMENT OF FISH MEAL PROTEIN BY LUPIN MEAL PROTEIN AND LUPIN PROTEIN CONCENTRATE IN DIETS OF NILE TILAPIA(Oreochromis niloticus).
In developing countries, there is a severe shortage of animal protein sources which resulted in dramatic increase in their prices. Aquaculture has the potential to overcome the animal protein shortage by increasing fish production through feeding fish balanced artificial diets. This spurs an effort to define and develop alternative ingredients, in particular, those of vegetable origin which are inexpensive ingredients. The present study following this effort is conducted, where lupin meal (LM) and its lupin protein concentrate (LPC) as a replacer for fish meal in Nile tilapia diets.
There were positive effects of producing protein concentrate in our laboratory from lupin meall on crude protein and negative effect on crude fat where the crude protein was increased but crude lipids were decreased.
Nine diets were prepared whereas the first diet is a control diet ( based on fish meal as a sole source of protein).The protein of fish meal was replaced by lupin meal protein and lupin protein concentrate at 25, 50, 75 and 100% replacement levels.
By the end of experiment (15 weeks) Nile tilapia fed a diet where 25% of fish meal protein was replaced by lupin protein concentrate expressed the best body weights when compared with those fish fed diets with 100% replacement. The same trend was obtained in terms of specific growth rate.Increasing the inclusion levels towards total replacement, fish fed diets with higher inclusion levels obtained poorer FCR and the differences were significant. PER and ANPU were better when fish fed lower inclusion levels of SBM or SPC.Normal body condition factors were obtained by fish fed the experimental diets. No mortalities were recorded in fish fed the experimental diets (100% survival).With exception of fish fed diet 9 (100% replacement) where the survival rate was 94%.
No significant differences were observed in carcass moisture and crude protein of fish fed the experimental diets but the opposite was true for carcass ash and crude lipids.Significant differences were detected in hepato-somatic indices and fish fed the total replacement of fish meal (diets 8 and 9) obtained the highest HSI. Significant differences in plasma protein and plasma glucose were found whereas fish fed the 100% replacement of fish meal obtained the lowest values.For economical evaluation, increasing the replacement level reduces the cost/kg feed but the profit index was reduced also for the higher inclusion levels (100%).From the results of the present investigation it could be concluded that 50% replacement of fish meal protein by lupin meal and lupin protein concentrate could be used in tilapia diets but for the best performance, nutritional and biochemical parameters with high profitability the 25% replacement of fish meal protein is recommended to be used in Nile tilapia diets