Digestibility of Local Feed Ingredients in Tilapia Oreochromis niloticus Juveniles, Determined on Faeces Collected by Siphoning or Stripping&#x0D;

Francis Pius Mmanda,Rukia Kitula,Anna Norman Haldén,Torbjörn Lundh,Jan Erik Lindberg,Matern S P Mtolera

doi:10.3390/fishes5040032

Abstract

Eight locally available protein source ingredients in Tanzania were selected for assessment of apparent digestibility (AD) in tilapia Oreochromis niloticus, using faeces samples collected by siphoning or stripping. The selected protein source ingredients were Lake Victoria sardines (FM), brewers spent yeast (BSY), moringa leaves (ML), freshwater shrimp (FSH), marine shrimp (MSH), cattle blood (CB), duckweed (DW) and fish frames (FF). The AD (%) of dry matter (DM), organic matter (OM) and crude protein (CP) was unaffected (p > 0.782–0.901) by the faeces collection method (i.e., siphoning or stripping), with correlation coefficient (r) of 0.98, 0.99 and 0.93 between AD values for DM, OM and CP, respectively, following siphoning and stripping. The AD (%) of DM, OM, CP and gross energy (GE) in the test ingredients differed (p < 0.0001). The AD (%) of DM and OM was lowest in BSY and DW, followed in increasing order by ML, MSH, FF, FSH and CB. In general, the AD (%) of CP was high (>76%), but with a low value (46%) for DW. The AD (%) of GE was closely correlated (r = 0.96) with the AD of OM. In conclusion, FSH, MSH, CB, FF, BSY and ML have acceptable protein digestibility to be used in tilapia diet formulation.

Highlights

Aquaculture production is continuously increasing worldwide to meet global market demand for fish and fishery products, driven by the diminishing of wild capture fisheries as the result of over-population and over-exploitation [1]
The present study showed that the estimated apparent digestibility (AD) of dry matter, organic matter and protein in tilapia was unaffected by the faeces collection method with high correlation coefficients between the methods (r = 0.93–0.99)
The results of the present study indicate that freshwater shrimp, marine shrimp, cattle blood, fish frames, brewers spent yeast and moringa leaves have acceptable protein digestibility to be used in tilapia diet formulation

Summary

Introduction

Aquaculture production is continuously increasing worldwide to meet global market demand for fish and fishery products, driven by the diminishing of wild capture fisheries as the result of over-population and over-exploitation [1]. 2019/2020 was 18,717 tons of which over 90% was tilapia fish production [3]. The number of tilapia fish farmers has gradually increased in Tanzania, resulting in a corresponding increase in demand for fish feed. The market price of commercial fish feeds available in the country is very expensive and unaffordable to small-scale fish farmers. The majority of tilapia fish farmers in Tanzania rely on locally available feed ingredients for their farmed fish [4].

Objectives

Methods

Results

Discussion

Conclusion