Efficacy of squid by-product hydrolysate supplementation on the growth performance, digestive enzyme activities and muscle growth-related genes expression of Penaeus monodon fed on plant protein-based diet

Abstract

The efficiency of squid by-product hydrolysate supplementation in the diet of carnivorous black tiger shrimp (Penaeus monodon) has been evaluated for 8 weeks. A low fish meal diet, containing 5% fish meal (unsupplemented control), was formulated and supplemented with graded levels of squid by-product hydrolysate at 0.5% and 1%. A positive control with 22% fish meal as the main protein source was also prepared. The growth in terms of weight gain (WG) and specific growth rate (SGR), nutrient retentions, digestive enzyme activities and muscle growth-related genes expression has been evaluated. Results revealed that WG and SGR of shrimp fed on diets supplemented with 0.5% and 1% squid by-product hydrolysate (WG:534.02–555.07%, SGR:3.30–3.36% day⁻¹) were comparable (p > 0.05) to the fish meal control (WG:544.03%, SGR:3.33% day⁻¹) and higher (p < 0.05) than the unsupplemented control group (WG:434.68%, SGR:2.99% day⁻¹). Similar trend has been observed in protein efficiency ratio (0.16–0.20), nutrient retentions (protein retention:10.95–13.42%, lipid retention:2.71–3.15%) and muscle growth-related genes expression (GLUT1:1.05–1.50, MHC:0.78–1.33, tor:1.09–1.43, 4e-bp:1.17–1.33; s6k:1.17–1.53). Total feed intake (988.11–1268.97 mg), feed conversion ratio (1.63–2.05) and survival (84.87–92.11%) were not significantly different (p > 0.05) among treatments. Moreover, digestive enzyme activities (protease:1010.13–1503.45 Units mg⁻¹protein, amylase:168.51–223.45 Units mg⁻¹protein, lipase:4510.93–5380.82 Units mg⁻¹protein) were not influenced (p > 0.05) by hydrolysate supplementations. These results suggest that the growth performance of P. monodon fed on a plant protein-based diet (with 5% fish meal) has improved upon the supplementation of at least 0.5% squid by-product hydrolysate in the formulated feed and is comparable to that of the shrimp fed the fish meal-based diet.

Keywords:

• squid by-products
• plant protein-based diet
• Penaeus monodon
• shrimp nutrition
• nutrient retention
• digestive enzyme activities
• muscle growth-related genes

PUBLIC INTEREST STATEMENT

Utilization of low fish meal or plant protein-based diets in shrimp are widely studied to lessen the fish meal dependence of aquafeed formulations. However, the use of plant proteins resulted in growth reduction in the cultured organisms and a decrease in harvestable biomass. To address this issue, squid processing by-product hydrolysate is supplemented in a low fish meal diet for carnivorous shrimp with the primary intention of evaluating if the hydrolysate could improve the feed value, comparable to a full fish meal diet, of a plant protein-based diet. Our results indicate that squid by-product hydrolysate supplementation improved the feed value of the plant protein-based diet, and enhanced shrimp growth and feed conversion efficiency comparable to a full fish meal-based diet. Collectively, our study suggests that the use of locally produced hydrolysate as a dietary supplement to plant protein-based diets can lessen the fish meal dependence of feed formulations.

Acknowledgements

The DOST-PCAARRD-Institute of Aquaculture, College of Fisheries and Ocean Sciences, UP Visayas project on the Improvement of Philippine Penaeus vannamei for Enhanced Growth and White Spot Syndrome Virus Resistance through Selective Breeding is acknowledged for the technical and operational support to this work. Ms. Rowena E. Cadiz, Ms. Emelyn Joy Mameloco and Mr. Alan N. Failaman are also appreciated for the technical assistance during the conduct of the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Department of Science and Technology-Science Education Institute Accelerated Science and Technology Human Resource and Development Program: Student Research Support Fund.

Notes on contributors

Maila V. Pan

Maila V. Pan, faculty of Zamboanga State College of Marine Sciences and Technology and Ph.D. student at University of the Philippines Visayas (UP Visayas). She works on bioconversion and utilization of industry by-products into bioactive feed additives for aquaculture.

Rex Ferdinand M. Traifalgar

Rex Ferdinand M. Traifalgar, Ph.D., Professor at UP Visayas. He is involved in research on the production of alternative feed materials and additives from underutilized marine invertebrates and fermented agricultural biomass for aquaculture use.

Victor Marco Emmanuel N. Ferriols

Victor Marco Emmanuel N. Ferriols, Ph.D., Professor at UP Visayas, with research interests in molecular biology, genetics and their applications in the aquaculture of bivalves and seaweeds.

Liberato V. Laureta

Liberato V. Laureta, Ph.D., Professor Emeritus at UP Visayas, with research interests in aquaculture energetics, marine benthos ecology and systematics.

Jose P. Peralta

Jose P. Peralta, Ph.D., Professor at UP Visayas, with research interests in fish hydrolysates as bioactive additives in human food and aquafeeds.