In the ever-evolving world of aquaculture, disease outbreaks and environmental stressors remain one of the main threats to fish health and farm profitability. Speaking at the 2025 Indonesian Aquafeed Conference in Jakarta on May 27, Dominique Bureau, Professor at the University of Guelph and chief scientific officer at Wittaya Aqua International, emphasized that the key to addressing these challenges may not lie in the medicine cabinet, but in the feed bag.
“Feeds are often the first and most practical line of defense available to aquaculture producers,” he said, emphasizing the logistical and regulatory constraints that make vaccines and antibiotics less feasible, particularly in warmwater species like shrimp, tilapia, and pangasius.
“However, while the market is flooded with a vast array of feed additives and formulations claiming health benefits, the actual efficacy of many remains unverified or misunderstood.” Through years of research and field testing, Bureau and his team are working to bridge this critical gap, bringing scientific rigor to the evaluation of functional feeds and identifying nutritional strategies that can realistically boost animal health, optimize feed conversion, and enhance economic returns.
Bureau’s approach is grounded in measurable impacts. Across hundreds of production farms from countries including Colombia, Vietnam, Thailand, Mexico, Egypt, and Indonesia, his team has amassed extensive data on feed conversion ratios (FCR), survival rates, and growth performance of Nile tilapia and shrimp. Their findings are striking: survival rates and feed efficiency are tightly interlinked, and small improvements can yield outsized economic benefits.
“For instance,” he explained, “in tilapia, reducing mortality rates from 50% to 80% can turn a losing operation into a profitable one, shifting margins from –16% to +12% annually.” Simulations show that higher mortality not only reduces biomass but also leads to poor feed utilization, higher FCR, and inefficient labor and energy use. The result? Profits evaporate.
Bureau emphasizes the need for a standardized index of mortality to objectively compare survival outcomes across systems, treatments, and geographies. A standardized Mortality Index (MI) was developed and is offered by Wittaya Aqua on its software platform. His team also conducts power analyses to determine the sample sizes needed for statistically meaningful studies, an often overlooked yet vital step in validating feed claims.
The research dives deep into how functional additives, such as high-dose vitamins, organic acids, probiotics, and plant-derived compounds, can boost resistance to pathogens like Vibrio, Edwardsiella, and Streptococcus. In multiple challenge trials, various compounds demonstrated significant reductions in mortality and improvements in growth.
In one study with Pacific white shrimp carried out at the APOTEC Research Center in Vietnam, dietary inclusion of specific feed additives reduced mortality rates by more than 50% following exposure to Vibrio. In Nile tilapia trials at the same center, experimental diets with select additives not only increased survival but also improved FCR and the stability and recoverability of fecal waste, a key benefit in intensive culture systems that have to actively remove solid wastes.
Figure 1. Economical FCR (Feed:Gain) vs. survival of Pacific white shrimp. Source: Wittaya Aqua International
Figure 2. Challenge trials and the effectiveness of additives against Vibrio. Source: Wittaya Aqua International and APOTEC
Scientific integrity in feed innovation
Yet for all the promise, Bureau urges caution. “We must remain vigilant about bias, especially when studies are driven by stakeholders with a vested interest in positive results,” he warned. “Repeatability and transparency are essential.”
To that end, he suggests designing controlled trials with robust parameters: using LD50 pathogen challenge protocols, varying environmental stressors (e.g., salinity, heat, pollutants), and comparing multiple dietary treatments. The goal is to assess not just if a compound works, but how, under what conditions, and whether the benefit justifies the cost.
Bureau’s research also highlights a surprising insight: sometimes less is more. In some trials, simply reducing or pausing feed during stressful events proved as or more effective than administering functional additives. With regards to environmental challenges, "nutrition alone can’t replace essentials like oxygen. We can’t feed our way out of poor water quality or overcrowding,” he noted.
Despite these caveats, the opportunity for targeted nutritional intervention is substantial. In benchmarking studies, the difference in FCR between average and top-performing tilapia farms represents savings of up to USD 200 per tonne of fish produced. “Who wouldn’t want to save USD 0.20 per kilogram of fish?” Bureau asked. “That’s real money.”
Toward a healthier future in aquaculture
As aquaculture continues to expand to meet the world’s protein demands, the sector must also grow smarter and more resilient. Bureau believes functional feeds, when evaluated and applied judiciously, can be a cornerstone of this evolution.
“We're not just feeding fish; we’re shaping the biology, economics, and sustainability of the entire industry,” he said. “That means making decisions based on evidence, not hype.”
In the complex world of aquaculture, it’s not just what you feed, but why, how, and when. And thanks to pioneers like Bureau, the answers are becoming clearer, one dataset at a time.
