07 April 2022 – Over the past three decades, advances in nutrition, genetics and hatchery techniques have helped increase global tilapia output from aquaculture. Unfortunately, along with this rapid development and intensification of the farming system, the industry has seen a concomitant rise in financial losses related to recurrent disease outbreaks and poor husbandry practices.
For example, tilapia production in many subtropical regions, like China, Egypt and Brazil, is often hindered by so-called seasonal “winter” or “summer” diseases, such as Francisella sp and Streptococcus sp., and other parasitic infections. And in the tropical regions of west Indonesia, the Philippines and south Vietnam – which are some of the most densely populated areas in the world – water and land constraints have forced intensification in poorly bio-secured systems, such as floating cages in freshwater reservoirs or land-based earthen ponds. In these production systems the deterioration of water quality and over-crowding can often result in mixed infections by different pathogens such as A. hydrophila, S. agalactiae and Tilapia Lake Virus (TiLV), which, in turn, can cause mass mortality events.
For over a decade, Phileo by Lesaffre has been developing yeast-based probiotics and postbiotics solutions to help tilapia producers navigate some of these major industry challenges. The company has now collected some of these into its AquaSaf Tilapia programme, which it sees as a one-stop approach that can help improve tilapia’s resistance to common production pressures by addressing various parameters.
In this Industry Perspectives, the company’s Global Species Manager, Otavio Castro, and its Global Programme Manager for Aquaculture, Alban Caratis talk Feedinfo through the programme in more detail and share with us their findings on the positive impact AquaSaf Tilapia can have on production.
[Feedinfo] Apart from regular disease outbreaks, what other pressing production challenges are top of mind for tilapia producers today?
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[Alban Caratis] While we know that disease outbreaks cause major economic losses for the industry, the overuse and misuse of antibiotics and antiseptics can also result in antimicrobial-resistant pathogens (AMR) and gradually reduce the effectiveness of the drugs available to farmers. From a food safety perspective, the presence of AMR organisms and chemical residues in the tilapia supply chain is also a potential route of exposure for everyone, subsequently affecting market access for tilapia, either through health regulations or change in consumer purchasing behaviour. |
In terms of nutrition, the progressive adoption of pelleted feed to supplement natural productivity in semi-intensive polyculture and monoculture pond systems has allowed producers to maximise yields, but it is not always a guarantee of profitability. Tilapia is a low-value species and feed accounts for up to 60% of the production costs. The optimisation of the economic performance of tilapia farming is a process that often starts with a well-managed feeding programme. Here cost savings on feed have become pressing, even more so as farm gate prices of tilapia have progressively declined due to lower export performances and the highly competitive farm segment.
Fish meal and fish oil have been largely and successfully taken out of tilapia diets over the past few years and replaced with vegetable alternatives, mainly soybean. However, the increasing price of commodities and the pressure to reduce feed formula costs have necessitated the utilisation of low nutritional value ingredients, such as cottonseed meal, sunflower oil, and rapeseed meal. Unfortunately, these are known sources of anti-nutritional factors that cause adverse physiological effects on fish gut and metabolism, reducing zootechnical performance and increasing the risk of chronic or acute health disturbances.
[Feedinfo] What are some of the interventions the industry has employed to tackle these challenges? And how successful do to you think they have been?
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[Otavio Castro] To address these challenges, the industry has placed a lot of effort in the development of vaccines to increase the disease resistance of farmed populations, and the selection of improved genetic strains to improve production performance. But while these interventions have proven to be a real game changer in other food industries (e.g., poultry and salmon), adoption in the tilapia sector so far remains limited to a handful of large industrial players. |
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Otavio CastroParallel to this, the disease burden on tilapia farms is increasingly threatening the economic viability of producers in Asia, Africa and Latin America. Yet almost none of the stocks of tilapia currently farmed around the world are preventively vaccinated prior or during production. As opposed to salmon where almost all stocks are currently vaccinated, the tilapia industry operates on small margins and vaccines are an additional farming expense which many farmers are not able to finance on their own. Also, most of the available vaccines for tilapia are administered by injection which constitute a significant barrier to its adoption by small and medium scale farmers.
The low sales price and the tight and fluctuating margins of tilapia are also not supporting the industry’s move towards more functional ingredients and challenge-specific feeds. Adoption barriers are much lower than for vaccines and genetic strains since most tilapia farmers globally already use commercial feeds for part or all of their production cycle. But functional ingredients suffer from a lot of misconception, and their cost effectiveness is often questioned by producers. We must also acknowledge the fact that feed producers have a hard time valorising functional feeds at farm scale due to the nature of the tilapia farming sector. In several cases the utilisation of functional ingredients is adopted when the problem is already established, and it is too late to help. Or they are adopted when there are some major basic factors that still need to be adjusted, such as feeding and nutrition, biosecurity and farming practices. This has resulted in the high prevalence of “black box” solutions in the feed additives segment where mode of action and benefits are not clear to farmers., Plus the approach of overpromising results and oversimplifying complex issues can lead to high expectations that are not met, and to the segment being discredited. With the growing challenges of the tilapia market, it is even more imperative than ever for feed producers to be able to glance inside the box and have explainable mode of actions so they can tailor the most cost-efficient functional solutions for their end customers.
[Feedinfo] What exactly does your AquaSaf Tilapia programme entail and how can it be off value to producers in addressing these production challenges?
[Alban Caratis] Phileo has developed yeast-based probiotics and postbiotics for the tilapia segment for more than 10 years. Over that time, we have progressively validated products and developed concepts that address some of the major tilapia production challenges, such as mass mortalities by infections from A. hydrophila and S. agalactiae, low growth patterns that are associated with chronic gut issues, economic losses due to poor feed conversion ratios, and reducing producers’ dependency on antibiotics. With a product like Safmannan®, for example, we have today concluded more than 10 R&D projects with tilapia – with as many production applications tested and new projects continuously entering the pipeline.
We feel that we are now reaching a reasonable level of maturity with our solutions for the tilapia industry, both in terms of coverage of the challenges faced by producers and our understanding of the mode of actions of our products. We are also able to accurately quantify their added value, whether it be in regard to the improvement of survival, FCR or extra income generated for the farmers.
The AquaSaf Tilapia programme encompasses all this hard work. It regroups all our solutions developed for tilapia in one place and provides our partners in the industry with gut health improvement and disease prevention strategies using our yeast probiotics and postbiotics.
The move to a programme is part of our strategy to no longer strictly promote the technological innovations contained inside our products, but to also communicate more about the value they bring to production. This should allow us to play a more pro-active role in supporting and empowering actors in the tilapia feed and farming industry.
[Feedinfo] Let’s look a little closer at the solutions making up the programme. How effective is your live yeast probiotic, ActiSaf®, at establishing gut health in tilapia? What are the findings you can share with us?
[Otavio Castro] As discussed previously, low demand for tilapia and high supply in many places around the world have resulted in low prices and increasingly tight margins. In this context, optimising production costs is a process that often starts with good feed conversion ratios and preserving the digestive ability of the fish.
Trials conducted by Phileo have demonstrated the potential for ActiSaf® to substantially increase midgut microvilli length and overall gut functionality when supplemented in tilapia diet, thus supporting higher nutrient absorptive capacity and resulting in a significant reduction of FCR and higher growth rate. In terms of reduction of FCR alone, we have demonstrated that ActiSaf® can generate feed savings of $120 per tonne of fish produced in commercial conditions, for an extra formulation cost incurred below $10 per tonne of feed.
[Feedinfo] You have also included Safmannan®, which you briefly mentioned earlier, to boost immune response. Once again, how effective is this solution at addressing the impact of disease on tilapia and improving their survival rates in an aquaculture setting?
[Otavio Castro] With average survival rates as low as 30% in some of the most exposed production systems, the ability of tilapia farmers to control disease outbreaks is imperative to secure profits and limit dependency on antibiotics.
Safmannan® is a purified yeast postbiotic with consistent concentration and ratio of β-glucans and mannans. We observed that in tilapia diets it can significantly improve the innate immune response by increasing the activation of lysozymes (an antimicrobial enzyme) in the gut mucus and by improving antibody levels (IgM) in the plasma. It also participates in pathogen exclusion and improves overall gut structure.
Under conditions of stress (e.g., over-crowding, low oxygen environments, high temperatures, etc.), this enhancement in immunity can limit the proliferation of some of the most common diseases in tilapia – such as A. hydrophila and S. agalactiae which we mentioned earlier – and result in a higher survival at harvest. In most of the challenge tests we have performed against these two diseases, using both juvenile and adult fish, we observed that Safmannan® reduced mortalities by half. These are substantial numbers for the many small and medium scale tilapia farmers around the world when you consider that they can easily engage up to $1,500 of capital for every tonne of tilapia produced and are often left with no option but to use antiseptic chemicals in case of disease outbreaks.
[Feedinfo] You have also included your selenium yeast solution, Selsaf®. How does it interact with your yeast postbiotics and probiotics to help with tilapia wellbeing and resilience?
[Otavio Castro] Selenium can be a limiting nutrient on fish immune responses. The selenoproteins, such as glutathione peroxidases and thioredoxin reductases, play a crucial role in the maintenance of cellular redox homeostasis in almost all fish tissues. The fish immune response itself, can trigger some pro-oxidant responses, where selenium can efficiently modulate the impact of reactive oxygen species.
Our data shows that Selsaf® is efficiently absorbed and stored in the muscle by fish and that it contributes to improving the animal’s overall oxidative status. In tilapia, it modulated cortisol levels after a challenge and synergistically improved some innate immune parameters when combined with postbiotics and probiotics, increasing and extending lysozyme and complement system activity.
By reducing oxidative stress generated from water temperature, high ammonia or even salinity, the animal remains closer to homeostasis and can channel more energy to fight diseases or grow.
[Feedinfo] Let’s talk about a bit about the economics. You are marketing AquaSaf Tilapia as a means for producers to boost fish resiliency and also economic returns. What is the impact this programme can have on producers’ bottom line?
[Otavio Castro] Sustainability is at the core of our company strategy. However, for us this is not just about environmental sustainability but financial sustainability too! Otherwise, any attempt to improve production practices and product safety in the sector would be all be for naught.
More to the economic performance of functional additives, the higher the challenge, and the earlier prevention starts, the greater the gains and chances of success. In fact, our tilapia programme has shown a substantial feeding cost reduction that resulted in gross margin gains above 20% in a field trial conducted in high challenge water condition in Philippines. We have also been able to show a 5% reduction in total fish production costs, followed by a 28% net margin improvement in a commercial trial conducted in Brazil during the grow-out phase (400g to harvest around 900g), where the field situation was not highly challenging. This big boost in margin was generated due to the greater performance in the fillet and industrial yield.
[Feedinfo] Are you investigating similar AquaSaf programmes for salmon and shrimp production? If so, are you seeing similar results?
[Alban Caratis] Presently we have several programmes that are well established in the livestock sector. AquaSaf Tilapia will be our first programme for aquaculture. Tilapia is one of our top three priorities, along with shrimp and salmon. So, while we started with the AquaSaf Tilapia programme, we are continuing our R&D efforts, with more research projects currently on-going and planned for 2022.
Concerning shrimp, we are at an equivalent level with tilapia – both in terms of R&D efforts deployed and the results observed – with successful applications to mitigate impacts caused by bacterial diseases, such as Vibrio sp, and improving performances in challenging situations such as super-intensive systems and in high/low salinities. Furthermore, we have been working extensively on palatability and performance improvement in reduced fishmeal diets. So, shrimp is definitely on our radar for our next AquaSaf programme.
In the salmon market, we are currently working on our strategy to better understand the current, most relevant challenges we can address and fine tune the best approaches for an AquaSaf Salmon programme. We also have solutions developed for rainbow trout and ongoing R&D projects within nutrition and health.
Published in association with Phileo by Lesaffre
