African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12257

Article in Press

Effect of phytase on nutrient availability and growth of juvenile Clarias gariepinus fed soyabean and groundnut-based diets


  •  Received: 05 February 2019
  •  Accepted: 05 February 2019
Abstract The research studied the effect of phytase to diets based on full fat soyabean and groundnut meal. Phytase addition significantly reduced phytate content in diets based on 25%, 50%, and 100% soya bean meal (P<0.05). Phytate hydrolysis was more effective with significant reduction achieved at 250 FTU/g compared to diets without phytase (Tukey, P<0.05). Significant interaction was observed for nutrient digestibility (factorial, P<0.05). Crude protein digestibility showed significant improvement with soyabean and phytase (Tukey, P<0.05). Regardless of phytase level, increasing soyabean level from 50% to 100% significantly improved digestibility of fat in the diet (Tukey, P<0.05). Phytase at 250 FTU/g showed the highest fat digestibility compared to other diets, including control (Tukey, P<0.05). Phosphorus digestibility was significantly improved with phytase at 1000 FTU/g compared to other phytase diet (Tukey, P<0.05). Weight gain declined with increasing substitution of fish meal by soya bean (Duncan, P<0.05), and irrespective of phytase levels (Tukey, P<0.05). However, significant improvement in weight gain of fish was observed with phytase addition to diets compared to diets without phytase (Tukey, P<0.05). Regardless of soyabean level, phytase at 250 FTU/g (P1) showed higher growth performance (Tukey, P>0.05) compared to 0 FTU/g (P0), 750 FTU/g (P3) and 1000 FTU/g (P4). In experiment 2, phytase effectively degraded phytate in groundnut meal with most phytate reduction (Tukey, P<0.05) achieved with phytase at 250 FTU/g compared to control and other phytase diet (Tukey, P<0.05). Phytase supplementation significantly improved crude protein, energy and lipid digestibility (Tukey, P<0.05). Phosphorus digestibility showed improvement with phytase addition compared to diet without phytase (Tukey, P>0.05). Phytate degradation improved growth performance of fish with phytase at 250 FTU/g compared to diets without phytase (Tukey, P<0.05). In conclusion, improvement in phosphorus utilization by phytase improved nutrient availability and growth performance of fish fed both diets.

Keywords: Phytase, Nutrient availability, soyabean meal, groundnut meal, Growth, Clarias gariepinus