Effect of fish meal replacement with guar meal concentrate on growth, food conversion, digestive enzyme activity and intestinal histology of Gilthead sea bream (Spars aurata)

The present study conducted to evaluate the effects of guar meal concentrate (Gmc) as substitute of fish meal on growth, digestive enzymes activity, and intestinal histological of seabream ( Sparus aurata ). Fish fed four experimental diets with a protein level set at 45 % for 12 weeks by replacing the 0 % (Gu0), 10 % (Gu1), 20 % (Gu2), and 30 % (Gu3) of fish meal with Gmc. The results showed that fish fed Gu2 elevated growth and feed utilization indices, respectively. Linear regression analysis revealed a significant negative relationship between Gmc inclusion and specific growth rate, and a positive relationship with feed conversion ratio. The protein body composition content rose when fish fed Gu2 and the lowest body lipid content noticed when seabream fed Gu0, the activity of the digestive enzymes lipase and amylase were reduced when seabream were fed Gmc at all levels. According to this trial, it is advantageous to supplement seabream diets with 10–12 % Gmc in formulated and balanced diets. • Fish fed diets containing Gu2 increased growth and feed utilization indices. • The activity of the digestive enzymes lipase and amylase were reduced when seabream was fed Gmc at all levels. • It is advantageous to supplement seabream meals with 10–12 % Gmc.