The effect of brown seaweed (Sargassum ilicifolium) powder on western white leg shrimp

The effects of substitution of seaweed, Sargassum ilicifolium, by replacing protein resources, in Litopenaeus vannameii diets was studied. It was carried out by incorporation of raw powdered seaweed at three levels, ۰% as control treatment, ۵% (C), ۱۰% (B) and ۱۵%(A)  each with four replications in isoprotein, (۳۳%) and isocaloric (۳۵۵kcal.۱۰۰-۱) diets.. Binder properties of seaweeds in different diet pellets were evaluated.  In laboratory conditions, ۴۸۰ shrimp juveniles (initial weight=۳ gram) acclimated in ۱۶ plastic tanks, fed ۴% of their biomass daily. During the ۴۵ day digestibility experiment, biometric indices were measured at ۱۵ day intervals to assess the growth performances. Based on physicochemical analysis of water at ۲ day intervals, effective parameters were maintained at a required range for the wellbeing of the shrimp during the experiment. Results of the experiment show that Sargassum sp. can be used as a binder in shrimp feed ingredients with significant differences between treatment pellet stability and water absorbance percent in sea water.Although initial biomass, SGR and survival rate showed no differences between treatments, but final biomass , biomass gain, FCR, shrimp flesh color and cholesterol levels revealed significant differences between treatments (p<۰.۰۵). The diet with the highest level of seaweed (A) showed not only the best growth performances, survival rate, change in the flesh color desirable to the consumers and decreased cholesterol level in shrimp, but also has the best binder property for shrimp pellet making.