Introduction

Fish feed represent the largest proportion of the production costs in aquaculture due to high cost of fishmeal and fish oil from fisheries which are the principal components of aquaculture feeds. Among different alternatives sources of proteins, macroalgae have been proposed as an alternative and renewable feeding resource for a sustainable aquaculture. Numerous evidences of the inclusion of macroalgae as supplement have been reported pointing to positive effects on fish growth, nutrient utilization, and disease resistance. Nevertheless, the effects of the use of macroalgae as fish meal replacement have been scarcely explored.

Objective

This study aimed to investigate the effect of replacing fish meal with Ulva lactuca at different level (5%, 10% and 15%) in the diet of Mozambique tilapia (Oreochromis mossambicus) on growth performance, feed utilization and hematological parameters.

Methodology

An 60-days feeding trial was conducted using 120 Oreochromis mossambicus (3.2 0.13 g) assigned to four dietary treatments group and three replication. The fish were fed with an algae-free control diet (C) and three experimental diets which replaced conventional fish meal with varying levels of Ulva lactuca (5%, 10% and 15%, represented as U5, U10 and U15, respectively).

The final weight (FW), weight gain (WG), percentage of weight gain (WG%) and specific growth rate (SGR) were statistical insignificant (P > 0.05) at all levels of algae incorporation including the control diet. However, higher growth performance can be observed on diet U5 than the fish on either of the U10 and U15 diets. The feed utilization parameters, feed conversion ratio (FCR) and protein efficiency ratio (PER) did not show significant differences among the diets, although poorer FCR and PER outcomes were observed on diet U5. Although, the hematology (leucocytes, erythrocyte, hemoglobin, hematocrit, mean corpuscular volume, neutrophils, Lymphocytes, mixed cells), showed no significant difference among the treatments except for platelets and Red Cell Distribution width, the results indicated U15 with better hematology performance.

Conclusion

From the results, it’s concluded that for better growth performance, fish meal can be replaced at 5% by U. lactuca without compromising its growth. On the other hand, U15 gives better hematology performance which may enhance the positive health effects.

Introduction

Fish feed represent the largest proportion of the production costs in aquaculture due to high cost of fishmeal and fish oil from fisheries which are the principal components of aquaculture feeds. Among different alternatives sources of proteins, macroalgae have been proposed as an alternative and renewable feeding resource for a sustainable aquaculture. Numerous evidences of the inclusion of macroalgae as supplement have been reported pointing to positive effects on fish growth, nutrient utilization, and disease resistance. Nevertheless, the effects of the use of macroalgae as fish meal replacement have been scarcely explored.

Objective

This study aimed to investigate the effect of replacing fish meal with Ulva lactuca at different level (5%, 10% and 15%) in the diet of Mozambique tilapia (Oreochromis mossambicus) on growth performance, feed utilization and hematological parameters.

Methodology

An 60-days feeding trial was conducted using 120 Oreochromis mossambicus (3.2 0.13 g) assigned to four dietary treatments group and three replication. The fish were fed with an algae-free control diet (C) and three experimental diets which replaced conventional fish meal with varying levels of Ulva lactuca (5%, 10% and 15%, represented as U5, U10 and U15, respectively).

The final weight (FW), weight gain (WG), percentage of weight gain (WG%) and specific growth rate (SGR) were statistical insignificant (P > 0.05) at all levels of algae incorporation including the control diet. However, higher growth performance can be observed on diet U5 than the fish on either of the U10 and U15 diets. The feed utilization parameters, feed conversion ratio (FCR) and protein efficiency ratio (PER) did not show significant differences among the diets, although poorer FCR and PER outcomes were observed on diet U5. Although, the hematology (leucocytes, erythrocyte, hemoglobin, hematocrit, mean corpuscular volume, neutrophils, Lymphocytes, mixed cells), showed no significant difference among the treatments except for platelets and Red Cell Distribution width, the results indicated U15 with better hematology performance.

Conclusion

From the results, it’s concluded that for better growth performance, fish meal can be replaced at 5% by U. lactuca without compromising its growth. On the other hand, U15 gives better hematology performance which may enhance the positive health effects.