EVALUATION OF FRESH AQUATIC PLANT (AZOLLAPINNATA) AND ARTIFICIAL DIET ON GROWTH PERFORMANCE, GASTRIC EVACUATION RATE AND CARCASS COMPOSITION OF NILE TILAPIA (OREOCHROMISNILOTICUS)

EVALUATION OF FRESH AQUATIC PLANT (Azollapinnata) AND ARTIFICIAL DIET ON GROWTH PERFORMANCE, GASTRIC EVACUATION RATE AND CARCASS COMPOSITION OF NILE TILAPIA (Oreochromisniloticus)

ABSTRACT

Alternative plant protein sources are generally cheaper compared to animal protein sources and may be the solution to reduce the high dependence of farmers on fish meal due to the limited world supplies and increasing price of fishmeal. This study focuses on growth performance of Nile Tilapia (Oreochromisniloticus); its gastric evacuation rate and carcass composition when fed with fresh aquatic plant and artificial diet. Azollapinnataand artificial diet (control) were fed at 3% body weight of 90 Oreochromisniloticusweighing 24±1.43g for 56 days (8 weeks) in three treatments T1(artificial diet), T2 (artificial diet 50% and aquatic plant 50%) and T3 (aquatic plant); each having  three replicates. Specific Growth Rate (SGR), Food Conversion Ratio (FCR), Protein Efficiency Ratio (PER), Mean Weight Gain (MWG), Protein Intake (PI) and Length-Weight Relationship were used to determine the growth performance and feed utilization. The serial slaughter method was used to determine Gastric Evacuation Rate (GER) and Gastric Transit Time (GTT). Proximate composition of fish carcass was determined using standard methods. Data were analysed using Descriptive analysis and ANOVA at α0.05. Fish fed both artificial diet and aquatic plant T2 attained a significantly higher MGW and SGR, and attained the best correlation coefficient value which indicates a good relationship between length and weight. T1 and T2 showed no significant difference in FCR but were significantly lower than T3. The PER showed that T2 was significantly higher than T1 and T3. Duncan’s test of significance indicated that there was no significant difference in the daily feeding rate and GER of Oreocromisniloticusacross the treatments but GTT differed in T3. Fish fed only Azolla, T3 had a GTT of 3 hours where as T1 and T2 was 4 hours. Carcass proximate analysis showed that crude protein of T3 was significantly higher than T1. Fat content of T3 was significantly higher than those of T1 and T2. Oreohchromisniloticusperformed better when fed with both artificial diet and aquatic plant, it also attained a higher crude protein level and lower moisture content when fed only aquatic plant compared to those fed only artificial diet. Key words: Oreohchromisniloticus, utlilization of aquatic plant, growth performance, gastric evacuation, carcass composition.

CHAPTER ONE

1.0       INTRODUCTION

1.1       Tilapia culture in Aquaculture

Food is a basic necessity of life, second only to air and water. The global food equation recognizes two major components namely; food crop component and animal protein component. Animal protein source include fish, poultry and livestock. Fish consumption in Nigeria is higher due to its comparatively cheaper price compared to protein from other livestock (Okonjiet al., 2013). Available fish for consumption comes from aquaculture and capture fisheries with the capture fisheries becoming less sustainable. Aquaculture is the husbandry of aquatic food organisms (mostly fishes). It involves breeding new fish stock, holding them in captivity and feeding them (Agbebi and Fagbenro, 2006), and it is believed to be a more sustainable source than capture fisheries. Report from the Food and Agriculture Organization (FAO) stated that Nigeria aquaculture industry produced over 30, 000 tonnes of fish in the year 2000; mostly tilapia (14,388 tonnes) cultivated under intensive and semi-intensive production system. Despite this status, the yield from aquaculture is