Table 1.

Presents the benefits and drawbacks of an alternative fish diet

Alternate Feed	Benefits	Drawbacks	Ref.
Guar meal	Guar meal may be substituted for soy meal without harming growth in certain fish.	This product includes antinutritional and anti-digestive substances such as residual gum, saponin, phytate, and protease inhibitor tannin. Gastrointestinal evacuation is slow. Indigestible amino acids. Oil production and guar gum usage affect the availability of guar meals.	[22,23]
Macroalgae	Bioactive compounds from macroalgae can help farmed fish.	Complex polysaccharides are indigestible Excess heavy metals The probable presence of phlorotannins, lectins, phyto acids, trypsins, and amylase inhibiting substances	[24]
Yeast	Lignocellulosic waste can grow Yeast protein is beneficial for fish, except for its low methionine content. Due to a rapid increase	Yeast protein is low in sulfur-containing amino acids such as methionine and cysteine.	[25,26]
Insects	Food waste may be used as a source of nutrients	Most insect diets were lacking in methionine and cysteine. Antinutritional chitin is reported.	[27]
Blood meal (cow blood)	The protein content is high. Lysine-rich	Methionine deficiency Protein digestibility is greatly influenced by heat sensitivity and drying conditions.	[28,29]
Hydrolyzed feather meal	Hydrolyzed feather meal is rich in cystine (74–61%) and protein.	Not easily digested Low in lysine and methionine (2 % of the crude protein) (1 % crude protein)	[30,31]
Wheat	Protein content is low (11%).	Wheat<apos;>s high starch content makes it a primary source of energy (usually more than 70%). There is a deficiency of lysine.	[32,33]
Microalgae and Algal oil	Microalgae<apos;>s rapid rate of growth A broad selection of species is available, each with a unique set of characteristics. ω-3 fatty acid-rich Contains antioxidants, colorants, and has a probiotic impact	Formulated feeds have a high production cost. Microalgae with rigid cell walls are difficult to digest.	[34,35,40]