The Growth and Mineral Utilization of Clarias Gariepinus Fingerlings Fed Phytase-Supplemented Toasted Lima Bean (Phaseolus lunatus) Diets

Orisasona O Ajani Ek

doi:10.4172/2155-9546.1000361

Abstract

Toasting causes slight reduction in the phytate content of Lima bean, thus requiring further treatment for effective utilization when incorporated into fish feed. The growth, mineral utilization and liver response of Clarias gariepinus fingerlings fed Toasted Lima Bean Meal (TLBM) diets supplemented with phytase was investigated. An Isonitrogenous diet (40% crude protein) was formulated with TLBM as a plant protein source. Phytase was added to diets post pelleting at 0 FTU (F1), 2500 FTU (F2), 5000FTU (F3), 7500FTU (F4) and 10,000FTU (F5). Feed were fed to triplicate groups of 15 fish (1.43 g ± 0.0012 g) stocked in 25 liter capacity plastic tanks, cultured at a mean dissolved oxygen, pH and temperature of 5.37mg/l, 7.2 and 25.8°C respectively for 56 days. Mean weight gain and Feed conversion Ratio (FCR) were significantly (P<0.05) higher in fish fed diets F3 and F4. Fish fed diets F4 had the highest Specific Growth Rate (SGR) 3.31, Protein Efficiency Ratio (PER) 1.78 and least FCR 1.41. The control (F1) gave the lowest SGR 2.79, PER 1.57 and highest FCR 1.6. There is increased phosphorus utilization with increased enzyme inclusion. Bone ash and phosphorus of fish showed mark increase with increasing level of phytase. Histopathological examination of fish revealed no negative effect of phytase on the liver of fish.

Highlights

Aquaculture is growing more rapidly than all other animal foodproduction sectors [1]
This growth is highly based on the utilization of fishmeal and fish oil, which contributes to the increasing cost of fish feed
Crude protein content was slightly higher in the toasted meal, while crude fibre and ash contents were marginally higher in the raw meal

Summary

Introduction

Aquaculture is growing more rapidly than all other animal foodproduction sectors [1]. The current increase can be partly attributed to the wide availability and utilization of aqua-feeds, which has a growth rate in excess of 30 percent per year [2]. This growth is highly based on the utilization of fishmeal and fish oil, which contributes to the increasing cost of fish feed. Lima bean is an important source of plant protein, with a production capacity in excess of 2000 kg/h reported [4]. It is well cultivated all across Nigeria and some African countries [5]. In addition to increasing cost of feed, the excretion of excess phosphorus in fish waste is a major concern

Methods

Results

Conclusion