Untitled

Abstract

Sea cucumber meal is proposed as ingredient for rainbow trout diet using an histological approach. Three isoproteic (crude protein 39.5%) and isoenergetic (18 MJ/kg DM) diets were formulated with increasing level of sea cucumber meal (FO10, FO15 and FO20; with an inclusion of 10, 15 and 20% of sea cucumber meal), these diets were tested against a fish meal based diet (FP). A monofactiorial balanced experimental design (3 x 4) was adopted. 48 trout, (110±7.5 g) of initial fish body weight, were utilized. The fish feed trial lasted in 49 days. At the end of experiment, histological sections of intestine and liver were sampled. All the tissue samples were stained with the Mayer hematoxylin-eosin (HE) stain while on the liver samples PAS, PAS diastase and Alcian Blue stains were carried out. The enteritis score showed a slight enteritis status in fish fed with sea cucumber meal, independently from inclusion level (FP: 6.13±0.35; FO10: 7.0±1.6; FO15: 7.38±1.77; FO20: 7.88±1.89). The inclusion of sea cucumber meal did not cause relevant histological changes in the intestine of rainbow trout, thus showing positive perspectives for its future utilization in fish feeds.