Fish meal production has been become static and sometimes follow decreasing pathway

Fish meal production has been become static and sometimes follow decreasing pathway. This issue led to increased fishmeal price. Regarding current fishmeal production volume and predicted aquaculture growth, the aquaculture will faced with severe bottleneck “fishmeal” (Gatlin et al., 2007; Naylor et al., 2009; Tacon & Metian, 2008). Sustainable growth of aquaculture together with maintain optimal fish growth and high quality product will be dependent on find an alternative protein source for fishmeal replacement. Fish as mono gastric animal needs high quality and quantity of protein in the diet. Due to high availability and low price, plant-base sources were the first choices as fishmeal replacement (Sanchez-Muros et al., 2014). Different plant protein sources such as: soybean meal, rapeseed meal, canola meal, pea, rice, wheat and corn gluten, lupine were used as partial and total replacement of fish meal. For the best performance, the ingredient should have high protein content, good amino acid profile, high digestibility and palatability and also it should not have negative effect on flesh composition from human nutrition point of view. In plant-base protein sources, high content of anti-nutitional Factors (ANFs) such as protease inhibitors, phytic acid, glocosinolats, saponins, lectin, phytostrogens, sinapinic acid, phenolic constituents have interfered with fish health (Francis et al., 2001). Although by using some techniques such as heat treatments, chemical and organic solvents can reduced the ANFs concentrations in feed stuff but this processing procedure is expensive, time consuming and in some cases will lead to decreased protein solubility and yield (Berot et al., 2005; Slawski et al., 2011a; Slawski et al., 2011b). Utilization of plant-based protein sources is limited by imbalanced essential and non-essential amino acid proportion (Barrows et al., 2008; Gatlin et al., 2007; Teles Aires et al.), low palatability (Hardy, 2010; Krogdahl et al., 2010; Teles Aires et al.), low digestibility (Krogdahl et al., 2010), low content of some amino acids such as: methionine, tryptophan, arginine and threonine (Krogdahl et al., 2010) and high content of fiber and non-starch polysaccharides (Francis et al., 2001). This unpleasant properties will caused reduced growth performance, decreased feed efficiency, extra nitrogen excrete and water pollution, also altering gut microbiota and intestine structure such as: shorter posterior gut folds, intestine enteritis and higher level of uptake of substances that not normally absorbed (Bakke-McKellep et al., 2007; Estruch et al., 2015; Ringo et al., 2008; Ringo et al., 2006), engrossed lamina-propria and submucosa that interfere in gut health and negative effect on nonspecific immune system , anti-oxidant capacity and disease resistance (Montero et al., 2015; Torrecillas et al., 2015).
All above mentioned undesired plant protein stuffs characteristics is taking an account as limiting factors for higher inclusion proportion of plant base protein in fish diet. Furthermore severe environmental problems such as deforestation of areas with a high biological value, massive water consumption, more utilization of pesticides and fertilizers and creation of transgenic varieties is accompanied with high plant incorporation in fish diets (Maria Alice & Miguel, 2005; Steinfeld et al., 2006). Additionally biofuel production and direct use for human consumption is another constrains to use of plant protein material (Moutinho et al., 2017).
From the other side, animal base protein sources were used as fishmeal replacement, but these ingredients are expensive and some of their unpleasant properties have limited its inclusion in fish diets. Meat meal, bone meal and poultry byproduct, have lower protein digestibility and also higher ash content interfere with intestinal absorption of nutrients and some trace elements such as Zinc (Hardy & Shearer, 1985). Blood and feather meal have low digestibility and their amino acid profile is different with fish requirements (Ayoola, 2010).