Phytogenic Feed Additives as a Sustainable Alternative to Antibiotics: Enhancing Growth and Disease Resistance in Nile Tilapia (Oreochromis niloticus) †
Animal Nutrition & Health R&D Center, DSM-Firmenich, 3430 Tulln, Austria
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Author to whom correspondence should be addressed.
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This article is a revised and expanded version of a paper entitled Bui Chau Truc, D.; Gruber, C.; Kesselring, J.; Standen, B.; Wein, S. Effect of a Phytogenic Feed Additive on the Growth Performance, Immune Response and Resistance against Streptococcus agalactiae of Nile Tilapia, Oreochromis niloticus. In Proceedings of the 78th Conference of the Society of Nutrition Physiology, Göttingen, Germany, 5–7 March 2024.
Animals 2025, 15(3), 380; https://doi.org/10.3390/ani15030380
Submission received: 7 December 2024
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Revised: 22 January 2025
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Accepted: 24 January 2025
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Published: 28 January 2025
(This article belongs to the Special Issue Advances in Functional Diets and Culture Conditions in Fish: Applications in Aquaculture)
Simple Summary
Disease outbreaks due to bacterial pathogens are among the biggest challenges in the aquaculture industry, resulting in mortality, impaired growth performance, and, subsequently, loss of profit. Antibiotic treatments are commonly used to control bacterial pathogens. However, since the development of antibiotic resistance is a concern, innovative antibiotic-free solutions are needed to replace their use. The usage of formulated functional aquafeeds incorporating additives, such as phytogenic compounds, represents a key strategy for enhancing animal performance and resilience against diseases. The results of two experiments with Tilapia demonstrate that phytogenic feed additives are promising strategies to improve fish production and provide increased protection against bacterial infection, independent of the diet formulation.
Abstract
Pathogens and challenging conditions in fish farming are common problems that cause mortality and reduce growth performance. Phytogenic feed additives can support the immunity of fish and thereby improve performance, production, and disease resistance. Two experiments with Nile Tilapia aimed to evaluate the effects of a matrix-encapsulated phytogenic additive (Digestarom® P.E.P. MGE) in different feed formulations, which vary in the marine meal inclusion level (5% and 12.8%), on growth performance and resistance against Streptococcus agalactiae. Fish were stocked in a recirculating aquaculture tank system per experiment and were fed with diets with or without the phytogenic supplementation for 8 weeks (six replicates per group). After an intraperitoneal injection with a sterilized saline solution and bath immersion with S. agalactiae (5 × 106 CFU/mL), mortality of the fish was recorded for 20 days. Independent of the diet formulation, the supplementation with the phytogenic feed additive significantly improved the fish production; feed conversion ratio; immune response (mainly lactic acid dehydrogenase, differential blood cell counts, and the lysozyme activity in blood); and fish survival after the S. agalactiae challenge. Thus, phytogenic feed additives are promising strategies to improve Nile tilapia production by enhancing fish growth performance, health, and protection against S. agalactiae infections.
