Effects of dietary substitution of fishmeal with the combined dry microalgae,Nannochloropsis oceanica(NO) biomass residue and casein on growth and body composition of juvenile abalone (Haliotis discus)

Abstract

The effects of dietary substitution of fishmeal with the combined dry Nannochloropsis oceanica (NO) biomass residue and casein on growth performance and carcass composition of juvenile abalone was determined. One thousand two hundred and sixty juvenile abalone were randomly distributed into the 18 L plastic rectangular containers. Five experimental diets in triplicate were prepared. The 28% fishmeal was included into the control (Con) diet. The 25%, 50%, 75% and 100% fishmeal were substituted with the combination of graded levels of dry NO biomass residue and casein, referred to as the NO25, NO50, NO75 and NO100 diets respectively. Finally, the salted sea tangle (ST), Laminaria japonica was prepared to compare the effect of the experimental diets on performance of abalone. The essential amino acids, such as isoleucine, leucine, phenylalanine, threonine and valine tended to increase with dietary substitution of fishmeal with NO biomass residue in the experimental diets. Arginine tended to decrease with dietary substitution of fishmeal with NO biomass residue. Survival of abalone fed the experimental diets was higher than that of abalone fed the ST diet for 16 weeks. Weight gain and specific growth rate (SGR) of abalone fed the NO100 diet were higher than those of abalone fed the all other diets. Weight gain and SGR of abalone linearly increased with dietary substation of fishmeal with NO. Shell length of abalone tended to increase with dietary substitution of fishmeal with the combined dry NO biomass residue and casein. The chemical composition of the soft body of abalone was different among treatments except for moisture content. In conclusion, fishmeal in the diets for abalone could be completely replaced with the combined dry NO biomass residue and casein when the 28% fishmeal was included.

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“…Crude protein and lipid content of the soft tissue directly related to dietary p rotein and lip id contents in this study, and agreed with other studies (Mai et al, 1995a, b;Thongrod et al, 2003;Cho et al, 2008;Garcia-Esquivel & Felbeck, 2009;Cho, 2010;Kim et al, 2015;Myung et al, 2016).…”

“…Biological criteria of abalone measured in this study (shell length, shell width, shell height and soft body weight), except for the ratio of the soft body weight to total weight seemed to be closely related to growth rate of abalone. Similarly, b iological criteria of abalone agreed with growth rate o f abalone (Bautista-Teruel et al, 2003;Cho, 2010;Myung et al, 2016).…”

“…Th is is why all 500 g/kg fish meal substituted diets with the fermented soybean meal regardless of substitution of MA with rice bran produced poorer weight gain in this study. Similarly, juvenile abalone (H. discus) fed the FMbasal diet with 250 g/kg fermented soybean meal achieved poorer weight gain than that fed the FMbasal diet with 250 g/kg soybean meal in the 16-week feeding trial (Cho, 2016;unpublished data). Nutrit ional values of fermented soybean meal varied depending on physical conditions of fermentation (Kook et al, 2014).…”

“…Similarly, MA common ly used as feed in wild did not produce the optimal performance of abalone (Lee, 1998;Cho et al, 2006;Kim et al, 1998;Naidoo et al, 2006;Cho et al, 2008;Gracia-Esquivel & Felbeck, 2009;Dang et al, 2011;Myung et al, 2016).…”

“…As FM and MA are the largest components of commercial abalone feeds and prices continue to increase, alternatively sources need to be identified and their performances evaluated against existing commercial feeds. Globally research has shown that a well formulated feed will produce better growth rates that a single algal species diet (Lee, 1998;Cho, Park, Kim, Yoo, & Lee, 2006;Kim, Lee, Han, Kim, & Park, 1998;Cho, Park, Kim, & Yoo, 2008;Naidoo, Maneveldt, Ruck, & Bolton, 2006;Gracia-Esquivel & Felbeck, 2009;Dang, Li, Speck, & Benkendorff, 2011;Kim et al, 2015;Myung et al, 2016).…”