The effects of a conventional feed versus a fish-free feed and biofloc management on the nutritional and human sensory characteristics of shrimp (Litopenaeus vannamei)

Abstract

Biofloc-based systems use little water and may recycle nutrients through the water column microbial community; fish-free diets may be more ecologically and financially sustainable than traditional feeds. A 12-week study examined the effects of biofloc (solids) management and a fish-free diet on shrimp quality. Four treatments were created; two used a conventional feed (including fishmeal and fish oil), one with solids management (CF-S) and one without (CF), and two treatments used a fish-free feed, one with solids management (FF-S) and one without (FF); each treatment was randomly assigned to four 3600-L tanks. The FF and FF-S shrimp had significantly lower lipid concentration and more manganese. Potassium was higher in CF-S shrimp versus CF; phosphorus was lowest in FF-S shrimp, and FF shrimp had the highest zinc levels. The CF shrimp had significantly higher omega-3s than FF shrimp, although omega-3 levels in FF shrimp were higher than the feed. This, coupled with higher omega-3 levels in the biofloc than the feed, may indicate that shrimp obtained some fatty acids from the biofloc material. The CF-S and FF-S shrimp had significantly greater sweet aromatic aroma, and the FF and FF-S shrimp had significantly higher first bite moisture release, mastication moisture release, and mastication fibrous/stringy texture. These results should be considered to optimize product quality of biofloc-raised shrimp fed fish-free diets.