Growth Performance, Enzymatic Activities, Haematology and Serum Biochemistry of Clarias Gariepinus Fed Thermally Processed Jatropha Curcas Kernel Meal Based Diets

Abstract

Abstract Jatropha curcas kernel meal is an agro-industrial by-product that is rich in essential nutrients that can be utilized by fish for optimal growth. The toxic substance and anti-nutritional factors (ANFs) must be removed to unlock its dietary potential. This study attempted to reduce the ANFs and improve the nutritional quality of J. curcas using autoclaving while the end product was used to replace soybean meal at 25%, 50%, 75% and 100% (TTR25, TTR50, TTR75 and TTR100 respectively) with the control (SBM) in prepared diets (40% CP) of Clarias gariepinus juveniles (n = 150, average initial weight = 18.21g). The results showed that thermal treatment reduced significantly the phorbol ester and other ANFs contents in J. curcas meal. However, the changes in the proximate compositions save for lipid content were insignificant. Further results after 63 days feeding trial showed that fish fed 25% (TTR25) J. curcas had the best weight gain (111.99 ± 14.53), feed conversion ratio (1.11 ± 0.16), protein efficiency ratio (1.41 ± 0.22) and survival rate (86.67 ± 11.55). Similar results were obtained in haematology, serum biochemistry and protease activity analysis with TTR25 fish emerging with the best results. However, the amylase and lipase activity results revealed that TTR75 and SBM fish had the best activities respectively. However, the results were not significantly different from that of TTR25. It is therefore concluded that J. curcas kernel meal can be rid of toxic substances and anti-nutrients through autoclaving while 25% replacement of soybeans with J. curcas kernel meal is recommended in the diet of Clarias gariepinus juveniles.