**5. Fish feed availability and the concept of valorization**

One of the solutions of fish feed availability is to entice animal feeds producing industries to consider also the production of fish feed [49]. However, the big issue here will be affordability; of these industrial feed products; most of our farmers belong to subsistence income bracket, hence, they might not afford these feed products. The use of floating pellets needs higher investment [50], which in most cases is lacking among smallholders; and unless the government intervenes in addressing the problems through either credit facilities or the provision of subsidies, the situation is not likely to get any better. It has been established that profitability in aquaculture is influenced by the cost of feed [51]. In Sub-Saharan countries, justification for industrial scale production of fish feed is not a priority despite the availability of raw materials [4]. Therefore, in order to feed fish, farm-made feeds can be made using locally available ingredients including animal by-products and plant residues.

In Tanzania, more than 80 percent of fish farmers relied on locally available feed ingredients as a major feed supplement for their cultured fish [43]. These local feed ingredients are categorized into four groups, (i) animal by-products, (ii) agricultural by-products, (iii) plant leaves and weed, and (iv) industrial by-products. It has been reported that the early growth phase of tilapia in 1991–2000 was significantly contributed by the use of alternative sources of protein including fishery by-products, terrestrial animal by-products, and a wide range of plant by-products [52]. In this chapter, discussion is cantered on the valorization of two broad categories of ingredients, plant and animal based ingredients.

#### **5.1 Plant based ingredients and by-products**

In addition to fertilization, feeding in ponds is done using supplementary feeds formulated on farm or purchased from cottage fish feed production industries. In some cases, cereal bran such as grains as energy source (**Figure 2**) and soybeans as

**61**

**Figure 3.**

*Animal Waste and Agro-by-Products: Valuable Resources for Producing Fish at Low Costs…*

source of protein (**Figure 3**) are used in aquafeeds to increase pond productivity. The production from this system ranges from 1000 to 2500 kg/ha/year [33]. Most farmers prefer this system since it is less expensive in terms of feed inputs. Ten edible plant leaves were evaluated (see in [54]) as potential feed ingredients for aquatic animal, the results suggested that some of the plant leaves used contributed on growth performance, immune system, and disease resistance for the fish. Other important plant leaves which have been subjected to experiments to see whether they can be used as ingredients for fish feed formulation includes cassava leaves [55] and *Moringa* leaf [56]. In another study results showed that the integration of vegetables (*Brassica oleracea*) as pond inputs increased fish production and net yield than those reared under non-integrated systems [57]. In general, the amount of grain and soybean required in the four East African countries is given in **Figures 2** and **3**. Another experiment (see [58]), showed that when wheat bran, rice bran, and groundnut bran were used as agro-industrial by-products to examine their economic effectiveness in fish production, there were variability in growth rate and economic benefits, suggesting that variability of agro-by products

According to the circular economy approach which focuses on the "reduce, reuse and recycle" of resources, waste from animal and food can be valorized leading to the production of proteins and other valuable compounds [59, 60]. For example, chicken, pig and cattle manures are substrates for production of housefly (*Musca domestica*) maggots which are in turn used as fish feed, or as supplement to fish meal in fish feed formulation [61]. Maggots are readily available and are accredited for having high nutritional value with an amino acid profile with biological value

*Amount of soybean required for fish feed coumpound in four countries of East Africa. Source [53].*

*DOI: http://dx.doi.org/10.5772/intechopen.95057*

reflects the growth rate of fish.

**5.2 Animal based ingredients and by-products**

**Figure 2.** *Amount of grains required for fish feed compounding in East Africa. Source [53].*

*Animal Waste and Agro-by-Products: Valuable Resources for Producing Fish at Low Costs… DOI: http://dx.doi.org/10.5772/intechopen.95057*

source of protein (**Figure 3**) are used in aquafeeds to increase pond productivity. The production from this system ranges from 1000 to 2500 kg/ha/year [33]. Most farmers prefer this system since it is less expensive in terms of feed inputs. Ten edible plant leaves were evaluated (see in [54]) as potential feed ingredients for aquatic animal, the results suggested that some of the plant leaves used contributed on growth performance, immune system, and disease resistance for the fish. Other important plant leaves which have been subjected to experiments to see whether they can be used as ingredients for fish feed formulation includes cassava leaves [55] and *Moringa* leaf [56]. In another study results showed that the integration of vegetables (*Brassica oleracea*) as pond inputs increased fish production and net yield than those reared under non-integrated systems [57]. In general, the amount of grain and soybean required in the four East African countries is given in **Figures 2** and **3**. Another experiment (see [58]), showed that when wheat bran, rice bran, and groundnut bran were used as agro-industrial by-products to examine their economic effectiveness in fish production, there were variability in growth rate and economic benefits, suggesting that variability of agro-by products reflects the growth rate of fish.

#### **5.2 Animal based ingredients and by-products**

According to the circular economy approach which focuses on the "reduce, reuse and recycle" of resources, waste from animal and food can be valorized leading to the production of proteins and other valuable compounds [59, 60]. For example, chicken, pig and cattle manures are substrates for production of housefly (*Musca domestica*) maggots which are in turn used as fish feed, or as supplement to fish meal in fish feed formulation [61]. Maggots are readily available and are accredited for having high nutritional value with an amino acid profile with biological value

**Figure 3.** *Amount of soybean required for fish feed coumpound in four countries of East Africa. Source [53].*

*Innovation in the Food Sector Through the Valorization of Food and Agro-Food By-Products*

One of the solutions of fish feed availability is to entice animal feeds producing industries to consider also the production of fish feed [49]. However, the big issue here will be affordability; of these industrial feed products; most of our farmers belong to subsistence income bracket, hence, they might not afford these feed products. The use of floating pellets needs higher investment [50], which in most cases is lacking among smallholders; and unless the government intervenes in addressing the problems through either credit facilities or the provision of subsidies, the situation is not likely to get any better. It has been established that profitability in aquaculture is influenced by the cost of feed [51]. In Sub-Saharan countries, justification for industrial scale production of fish feed is not a priority despite the availability of raw materials [4]. Therefore, in order to feed fish, farm-made feeds can be made using locally available ingredients including animal by-products and

In Tanzania, more than 80 percent of fish farmers relied on locally available feed ingredients as a major feed supplement for their cultured fish [43]. These local feed ingredients are categorized into four groups, (i) animal by-products, (ii) agricultural by-products, (iii) plant leaves and weed, and (iv) industrial by-products. It has been reported that the early growth phase of tilapia in 1991–2000 was significantly contributed by the use of alternative sources of protein including fishery by-products, terrestrial animal by-products, and a wide range of plant by-products [52]. In this chapter, discussion is cantered on the valorization of two broad catego-

In addition to fertilization, feeding in ponds is done using supplementary feeds formulated on farm or purchased from cottage fish feed production industries. In some cases, cereal bran such as grains as energy source (**Figure 2**) and soybeans as

**5. Fish feed availability and the concept of valorization**

ries of ingredients, plant and animal based ingredients.

*Amount of grains required for fish feed compounding in East Africa. Source [53].*

**5.1 Plant based ingredients and by-products**

**60**

**Figure 2.**

plant residues.

exceeding that of soybean and groundnut. Maggots can be harvested, processed into a meal that can be used to substitute or replace fish meal [61, 62]. Maggot grown on a mixture of cattle blood and wheat bran contained 92.7% dry matter, 47.6% crude protein, 25.3% fat, 7.5% crude fiber, 6.25% ash, and an amino acid profile comparable to fish meal [59] suggesting that animal wastes utilization can be used to produce insects which can be utilized as fish feed hence, reduce feed cost significantly, thus leading to a viable and sustainable aquaculture industry. The replacement of 25 percent fishmeal in catfish feed, culture with maggot gave high growth performance and profitability than fishmeal based diet [63, 64]. Several researches [65, 66] have been reporting on the use of red worms, black soldier fly, common housefly, and yellow mealworm as a source of protein to replace fishmeal. It is envisaged that the valorization of animal and animal by-products such as animal blood, offal of poultry, residues of traditional brewery waste, animal manure and fish wastes may contribute significantly on fish production hence, food nutrition and security.
