Growth response and feed utilization in Clarias gariepinus fingerlings fed diets supplemented with processed flamboyant (Delonix regia) leaf meal

S.A Adesina,O.D Agbatan

doi:10.4314/as.v20i1.7

Abstract

Expanding utilization of conventional fish feed ingredients by man and fish feed industries has necessitated consideration of cheaper and locally available alternatives. A 70-day feeding trial was conducted to assess the effect of substituting graded levels of sundried flamboyant (Delonix regia) leaf meal (SFLM) for groundnut cake on growth and feed utilization of 240 Clarias gariepinus fingerlings at six substitution levels of 0 (control), 20, 40, 60, 80 and 100% in 12 plastic aquaria (50 × 40 × 40 cm). Each dietary treatment was randomly assigned in two replicates each to the aquaria making 12 treatment units and each aquarium had 20 fish. SFLM supplemented diets and fish carcass were proximately analyzed using standard procedures. Mean weight gain (MWG), specific growth rate (SGR) and feed conversion ratio (FCR) were determined. Data obtained were analyzed using descriptive statistics and ANOVA at p ≤ 0.05. Crude protein was highest (68.89%) in fish fed with diet 4, least (64.61%) in fish fed with diet 1 (control) and significantly (p < 0.05) exceeded 60.54% of the pre-treatment fish carcass. Fish fed with diet 3 had significantly (p < 0.05) higher values of MWG (11.73 g), SGR (2.13%/day) and superior FCR (0.451) above which growth and feed utilization indices progressively declined with increase in the substitution level of SFLM. This study revealed that 40% substitution level of the SFLM resulted in the best growth and feed utilization in C. gariepinus. The study demonstrated the considerable potential of flamboyant leaf meal as an alternative protein source, therefore other processing methods are recommended to increase its utilization, reduce feed cost and maximize aquaculture profitability.

Highlights

As the need to improve and sustain human food security among economically challenged developing countries is highly imperative, aquaculture has been identified as an increasingly suitable option for improving animal protein intake from 40 to about 60% in order to achieve expected sustainable development goal (Afe and Omosowone, 2019)
Proximate Composition of Test Ingredient and Experimental Diets Table 2 shows the proximate composition of sundried flamboyant leaf meal and other ingredients used in the experimental diets
The specific growth rate (SGR) values obtained in this study suggested superior growth response compared to 0.25-0.59% day–1 reported by Adesina and Ikuyeju (2019) for C. gariepinus fingerlings fed pawpaw leaf mealbased diets and 0.44-1.81% day–1 observed by Anyanwu et al (2008) for hybrid Heteroclarias (H. bidorsalis × C. gariepinus) fingerlings fed A. cordifolia leaf meal-based diets

Summary

Introduction

As the need to improve and sustain human food security among economically challenged developing countries is highly imperative, aquaculture has been identified as an increasingly suitable option for improving animal protein intake from 40 to about 60% in order to achieve expected sustainable development goal (Afe and Omosowone, 2019) This target can only be feasible through identification and utilization of high-quality feedstuffs which are rich in protein and other essential nutrients in a bid to improving growth without compromising the animal’s general wellbeing (Soltan and El-Laithy, 2008). Bake et al (2014) reported that inadequate supply, rising demand and high cost of fishmeal are among several challenges facing the sustainable development of aquaculture industry, the need to attempt broader utilization of cheaper protein-rich ingredients from plant and animal sources for the production of costeffective and eco-friendly fish feeds. The increasing scarcity of these protein sources and competitive demand from other sectors for human use, livestock consumption and industrial purposes continue to heighten their costs far beyond the reach of most fish farmers and fish feed manufacturers (Fasakin et al, 1999)

Methods

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Discussion

Conclusion