CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
The growth and viability of the aquaculture sector depend heavily on feed (Olasunkanmi et al., 2021). The most expensive ingredient that has a direct impact on feed consumption, fish growth, and feed costs is protein, which is typically a significant component of fish feeds (Aragão et al., 2022).
The general consensus is that fish require more protein in their diets than other animals. The majority of fish species eat as predators, and many species are forced to adopt a carnivorous feeding behavior in order to meet the high protein requirements. The anabolic process (growth) of the fish body is only reflected by the protein, which is the only significant nutrient. Fish use amino acids as energy substrates, which is one of their primary characteristics. They prefer to use amino acids as a source of energy rather than glucose (Radhakrishnan et al., 2020).
The most preferred aquaculture feeds for years have been fish meal and fish oil of marine provenance (Boyd, 2013). A 38 million tonne increase in annual feed output is required if the aquaculture industry is to meet its growth goals by 2025.
Unfortunately, the annual output of fishmeal around the world fluctuates between 4.5 million tonnes, 69% of which are used as fish feed. Since aquaculture already consumes 75% of the yearly output of about 0.9 million tonnes of fish oil, there is even less room for maneuvering. Due to their scarcity and high cost, both commodities are limited (Eurofish International Organization, 2022).
However, as the aquaculture sector becomes more aware of costs and benefits, researchers are looking into options to develop more sustainable replacements that improve fish health and deliver the same nutrients to consumers (Elliott, 2019). For many years, studies on the replacement of fishmeal were performed on a variety of aquacultured species, and the growing body of research papers suggested that some of them could be raised on feeds without fishmeal and amino acid supplements.
Studies currently being conducted on possible substitutes for fishmeal and fish oil evaluate not only their effects on growth but also the health of the fish and the quality of the meat (Catacutan, 2017). Plant-based sources, rendered byproducts, sources from land- and sea-based animals, as well as some unusual constituents, are among the numerous feed components that have been tested as substitutes for fishmeal and fish oil. Many types of legumes, cereal grains, oil seeds, and leaf meals have been evaluated in a large number of aquaculture nutrition studies because they are thought to be limitless sources ( (Catacutan, 2017).
Numerous studies have demonstrated that sources of vegetable protein have a high potential for providing fish with the necessary protein for their optimum productivity (Nwanna et al., 2008). Some of the plant protein sources that have been investigated in an attempt to find substitutes for fish meal in the diets of fishes include; Leucaena, Sesbania,Sweet potato, Mulberry, Acacia, Papaya, Water hyacinth, Duckweed, Duck lettuce, Water snowflake and Peanut. In the majority of these studies, the leaf meals could only replace about 25% of the protein in fishmeal (Idowua et al., 2017).
Recently, researchers have become more interested in Moringa (M. oleifera Lam). The only genus in the family Moringaceae is Moringa, a native plant to Africa and Asia and the most popular variety for cultivation in Northwestern India. It consists of 13 varieties from tropical and subtropical regions that range in size from tiny herbs to enormous trees, with Moringa oleifera being one of the most researched (Vergara-Jimenez et al., 2017). The M. oleifera plant grows quickly and is rich in macro and micronutrients, including proteins, carbohydrates, vitamins, minerals (phosphorus, calcium, potassium, iron), beta carotene, and other bioactive compounds (Sahay et al., 2017).
It is widely available and, due to its high nutritional quality in fish diets, can be used as a potential replacement for fish meal (Khetran et al., 2018). The crude protein content of its leaves is 260g/kg, which is much greater than that of soybean seeds and other legumes (Ferreira et al., 2008). This plant is commonly referred to as a multi-purpose plant because of its numerous uses in pharmaceutics, agriculture, livestock, human, and other biological systems (Falowo et al., 2018). According to one research, its leaves contain a high range of protein contents ranging from 25% to 32%, as well as a low number of tannins and other anti-nutritional elements (Nouala et al., 2006).
The family, Claridae is a significant catfish species with commercial significance in Nigeria. Due to their rapid growth rates, disease resistance, tolerance to high density culture, ability to grow on a variety of natural and inexpensive artificial feeds, and ability to withstand low oxygen and pH levels, two significant members of this family, Clarias gariepinus and Heterobrachus bidorsalis, are prominent in African aquaculture (Gbadamosi and Osungbemiro, 2016).
Even though investigations have been made into how the growth of Clarias gariepinus is impacted by the Moringa oleifera. Little is known about the effect of the plant on the protein content of C. gariepinus. Thus, the purpose of this study is to ascertain how Clarias gariepinus's development characteristics and protein levels are affected by various amounts of Moringa oleifera leaf meal.
1.2 Aim of the Study
The study is aimed at determining the effect of varying levels of Moringa oleifera leaves on the growth and protein level of Clarias gariepinus (African catfish).
1.3 Objectives of the Study
The study had the following specific objectives:
- Evaluate Clarias gariepinus’ performance in terms of growth rate when fed on varying levels of Moringa oleifera leaf meal.
- Evaluate the effect of graduated amounts of Moringa oleifera leaf diet on Clarias gariepinus protein levels.
1.4 Statement of the Problem
The primary supply of animal protein in the diets of fish, livestock, and poultry is fishmeal. Despite being a significant component, its high cost and antinutritional qualities are the main factors limiting feed formulation. When used in the process, it increased the cost of feed and the corresponding increase in fish production (Ekelemu et al., 2000).
Thus there has been a great deal of emphasis placed on the use of conventional plant protein sources that are less expensive and readily available resources to replace fish meal without reducing the nutritional quality of the feed. Recently, researchers have become more interested in Moringa (M. oleifera Lam) (Aminu et al., 2022).
On the other hand, wild-caught and farmed seafood is a major source of animal protein for more than 3 billion people worldwide. Seafood is the most widely exchanged food product in the world and feeds billions of people. Fish consumption becomes a crucial component of the diet because the human body cannot produce substantial amounts of these essential nutrients (World Wildlife Fund, 2023).
The African catfish is low in carbs but high in protein. Catfish feed has typically contained 32–35% dietary protein. Commercial catfish feeds contain a lot of relatively expensive, high-quality protein, and since feed costs are the main variable operating costs related to catfish production, a lot of effort has been put into developing alternative fish feeds required to achieve the best dietary protein levels in catfish (Robinson and Menghe, 2007).
1.5 Justification of the Study
If the aquaculture business is to continue to grow, it is crucial to find substitute protein sources for fishmeal in fish feed. The results of this research will therefore be crucial in determining the ideal proportion of Moringa oleifera leaf meal to include in specially designed Clarias gariepinus diets.
In the end, the analysis provided in this study will assist further interested researchers in the subject area to conduct additional studies on various study designs.
1.6 Scope of the Study
The scope of the study covers the effect of varying levels of Moringa oleifera leaves to the growth and protein level of Clarias gariepinus (African catfish).
