With the fast-growing shrimp sector facing a number of challenges, Phileo by Lesaffre is launching Aquasaf Shrimp, a comprehensive guide for producers. Aiming to help maintain health, growth and profitability, the programme provides practical guidance on the use of fermentation solutions, backed up with both lab and on-farm trial results.
Discussing the guidance in today’s Industry Perspectives piece, Dr Jean-Benoît Darodes de Tailly, Global Programme Manager for Aquaculture at Phileo by Lesaffre, explains that it builds on a decade of research and development focused on yeast and bacteria, probiotics and postbiotics, and follows the launch of its Aquasaf Tilapia programme two years ago.
Given the issues that shrimp farmers have to address, this guide is timely. “The on-farm challenges facing shrimp producers include disease, inconsistent growth, feed performance from chronic oxidative stress and gut dysbiosis, as well as the reliance on marine ingredients and antimicrobial substances,” Dr Darodes de Tailly said. “The programme is based round three key pillars, providing solutions for these critical issues,” he added.
[Feedinfo] Shrimp farming is a fast-growing sector globally, yet it has some unique and difficult challenges. Can you tell us more about the sector and the issues that producers face?
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[Jean-Benoît Darodes de Tailly] For decades, shrimp farming has thrived on its reputation as a risky yet highly profitable activity, attracting many new producers. Recently, however, it has been confronted with a series of new challenges; oversupply, reduced demand due to inflation, higher production costs from intensified farming, and recurrent disease outbreaks. New diseases – the main issue for farmers – appear regularly, about once every five years or so. This is all the more challenging due to the shrimp’s primitive immune system, which explains why there are no commercially available vaccines. Additionally, shrimp are benthic feeders, constantly foraging the bottom for food, and are often exposed to high concentrations of pathogens. |
Dr Jean-Benoît Darodes de Tailly |
Apart from the white spot syndrome virus, which can cause complete crop failures in a matter of days, diseases targeting the gut remain the most concerning for farmers. I'm referring here to those linked to parasites such as EHP and pathogenic bacteria like Vibrio spp. causing EMS (Early Mortality Syndrome) for example. White Faeces Syndrome, which can result from pathogens and other stress factors, is also a major concern since shrimp die off slowly and convert feed pellets badly, resulting in significant financial losses.
TPD (Translucent Post-Larvae Disease) is the latest arrival and is now a substantial threat for hatcheries and farmers in Southeast Asia. Its prevalence is increasing rapidly and recent publications have pointed towards a specific strain of V. parahaemolyticus as the main causative agent of this emerging disease.
Health is often compromised for cost saving purposes and can be responsible for a lot of hidden costs when mis-managed. Additionally, there is a general trend towards intensification, which results in increased dependence on formulated diets and a higher prevalence of diseases on farms. When a pathogen breaches a pond in such an intensified environment, things can go wrong very quickly.
With such challenges, it is becoming harder to produce shrimp, and farmers need to adapt their practices to remain profitable, particularly in the current context of prolonged low prices. Progress has been made in the past decade in terms of feed quality and performance, but we still see considerable room for improvement in terms of health management and functional nutrition to limit the impact of diseases.
[Feedinfo] You are releasing Aquasaf Shrimp, providing practical guidance on the use of fermentation solutions in order to tackle some of these issues. There are three key pillars to this – can you give us a brief overview of these?
[Jean-Benoît Darodes de Tailly] The Aquasaf Shrimp program provides expertise and practical solutions to address key challenges encountered in intensive shrimp farming, focusing on fermentation solutions derived from both yeast and bacteria.
These challenges include disease, inconsistent growth, feed performance from chronic oxidative stress and gut dysbiosis, as well as the reliance on marine ingredients and antimicrobial substances. Therefore, our approach is structured around three pillars.
The first pillar is managing gut health and microbiota against dysbiotic conditions utilising yeast and bacterial probiotics.
The second pillar is controlling shrimp mortality by bolstering immune function, promoting exclusion of pathogens, and improving stress resistance to address specific challenges using yeast probiotics.
The third pillar is supporting fishmeal substitution while maintaining growth and performance, using yeasts which are rich in essential amino acids, peptides, vitamins, minerals, and immune-boosting compounds.
[Feedinfo] Gut health is pivotal for optimal growth, immunity, and overall welfare, yet it is disrupted by many environmental factors. What has your work focussed on to overcome this?
[Jean-Benoît Darodes de Tailly] Our recent work has focussed on the use of yeast and bacterial probiotics to improve shrimp gut health and production performance i.e. FCR, survival, growth. The gut plays a vital role in shrimp well-being and performance as the hub for digestion, nutrient absorption, and immune defence. Maintaining gut health is pivotal for optimal growth, immunity, and welfare. When talking shrimp digestive system, we mostly have the hepatopancreas in mind as it plays a significant dual role, contributing to digestion and immunity.
Probiotics offer numerous advantages for positively influencing gut health, including outcompeting harmful bacteria, releasing enzymes that break down complex feed components, and modulating immune responses. Our probiotics offer all of the above, and flexibility in their application methods, including water application, top-coating, pond-side fermentation, and fermentation of raw materials.
To help establish and maintain a beneficial and stable gut microbiota, we rely on Microsaf®, a versatile solution capable of supporting growth throughout the whole production cycle. It comprises of selected strains of Bacillus pumilus, B. licheniformis, and B. amyloliquefaciens, each chosen for their strain-specific activities. Ensuring the efficacy of bacterial probiotics poses a challenge in shrimp, given their digestive transit time of 3-4 hours. To address this, we have developed the GO-technology, a patented innovation that enhances germination of spore-forming bacteria probiotics. It’s quite ground-breaking as enables spores to germinate within minutes, compared to several hours for non-treated ones.
Actisaf®, our live yeast concentrate in microspherule form, is recommended to prevent and mitigate gut disorders, particularly when shrimp face specific challenges, such as a known presence of vibrio and EHP in the pond. In shrimp challenged with this parasite, we observed a clear improvement in the condition of the hepatopancreas, including a reduction in the proportion of deformed hepatopancreas tubules. This demonstrates our yeast's ability to mitigate the damage caused by gut pathogens and potentially enhance the animal's resistance to secondary infections.
We believe the observed benefits of our live yeast are likely attributed to their combined prebiotic and probiotic actions, both from beta-glucans and MOS on one side, and metabolites and enzymes on the other. So, it’s not only about the yeast itself but also what it releases into its environment. For example, previous published research on Actisaf® in tilapia has demonstrated that the metabolites it produces can reduce gut inflammation, with Actisaf® supplementation reducing the expression of heat shock protein compared to inactivated yeast.
[Feedinfo] The shrimp industry has to deal with a wide range of pathogens, including bacteria, viruses, fungi, and parasites, all of which can lead to mortality. Can you talk us through your approach to managing this pillar?
[Jean-Benoît Darodes de Tailly] Diseases arise when one of the three vital components of the epidemiological triad— comprising the pathogen, its host, and its surrounding environment —is thrown out of balance.
Our yeast solutions for mortality control primarily target the first and second aspect of the triad, while our probiotics act on the third, the environment of the gut, so we provide a holistic solution.
In terms of the first and second aspect, we are focusing on pathogen binding and on the shrimp itself. This is achieved through reducing pathogen pressure in the gut and stimulating the immune response. Our yeast cell wall Safmannan® diminishes pathogen loads in the gut due to its alpha-mannans content, and bolsters immune response through its 1.3-1.6 beta-glucans.
Vibrio spp., which encompass most of the pathogenic bacteria commonly found on shrimp farms, exhibit a strong attraction to mannan oligosaccharides (MOS). Bacteria will bind with Safmannan® particles and subsequently be expelled through the faeces. MOS can also attach to receptors present on the gut epithelium, reducing the number of sites available for harmful bacteria to adhere to, alleviating gut pathogen pressure. A challenge trial at the University of Can Tho in Vietnam confirmed Safmannan®'s efficacy in safeguarding shrimp gut health against EMS-induced alterations, preserving hepatopancreatic cell differentiation and morphology.
The second mode of action involves boosting the shrimp's immune system with beta-glucans. Beta-glucans, recognised as Pathogen Associated Molecular Patterns (PAMPs), trigger the shrimp's innate immune response, inducing both cellular and humoral components even in the absence of infection. Following infections with V. parahaemolyticus, we observed significant enhancements in shrimp immune parameters, particularly an increase in quantity and activity of immune cells. The ultimate goal is to achieve improved survival rates post-infection, and we’ve seen up to 1.8 times more survival compared to challenged shrimp fed standard diets against V. parahaemolyticus after 10 days of infection. Survival curves from trials also showed a strong deceleration in the initial rate of shrimp mortality with Safmannan® supplementation, providing farmers with valuable time to conduct water exchange or emergency harvests, potentially averting total crop failure.
To reduce stress and avoid diseases, another key strategy involves optimising and maintaining stable water quality parameters—the third component of the triad. This can seem trivial but for example, oxygen values can fluctuate heavily. Having 8ppm at noon and barely 3ppm just before sunrise is not uncommon, causing stress and making shrimp more vulnerable to pathogens. Selsaf®, our organic selenium from yeast, is a powerful antioxidant and helps mitigate shrimp oxidative stress resulting from unstable or poor water quality, and chronic infections.
[Feedinfo] The desire to move away from using fishmeal in diets has provided a challenge for the shrimp sector. What are the main issues – nutritional and functional – and how have you managed to overcome these?
[Jean-Benoît Darodes de Tailly] Feed represents the main operational cost of shrimp farms, making efficient feeding key for economic sustainability. Historically, aquafeed millers relied heavily on fishmeal (FM) for its ideal nutrient composition, high attractability and digestibility. However, it is now a strategic, low-inclusion ingredient due to high and volatile market prices. Plant-based ingredients, such as soybean, have become the most common alternative to substitute FM in aquafeeds. Now we have reached a point where further inclusion isn’t possible without compromising health and performance, but we offer functional solutions/proteins to push this barrier further.
One crucial aspect to consider is the reduction in feed attractability and palatability. Feed attractability refers to the speed at which shrimp locate and move towards feed, while palatability determines whether or not the shrimp will ingest it once they find it. Shrimp differ significantly from carnivorous fish in this aspect, as they primarily rely on chemical cues to detect pellets at the bottom of ponds. Shrimp have a narrow window of about two hours to locate feed before its scent dissipates. Low attractability results in reduced detection, leading to high feed conversion ratios (FCR) and degraded water quality due to unconsumed feed pellets decomposing in the pond.
Our yeast extract, Prosaf®, is rich in low molecular weight compounds, with over 88% of its peptides measuring below 3.6 kDa. These small molecules are renowned for their ability to enhance attractability and palatability. In trials with whiteleg shrimp, we observed feed intake levels over 5% higher when 3% FM diets were supplemented with Prosaf® compared to the same feed at 3% fishmeal. Additionally, incorporating 2% Prosaf® matched the consumption levels seen with 2% krill meal, positioning it as an equal to high-quality marine ingredients.
Our second tool is Nutrisaf®, our yeast fraction derived from S. cerevisiae through autolysis. This cost-effective functional protein source rebalances essential amino acids in plant-based diets, enhancing performance and boosting immunity for optimal health in shrimp. In trials with L. vannamei, even minor additions of Nutrisaf® to diets containing 20% FM and 13% peanut meal resulted in a significant performance boost, similar to the control diet featuring 25% FM. Additionally, only 2% inclusion of Nutrisaf® led to a 13% reduction in FCR, highlighting its economic viability in FM-replacement strategies. A challenge test with pathogenic V. parahaemolyticus on shrimp fed with Nutrisaf® showed significant improvements in shrimp immune status, particularly crucial in diets with low FM inclusion levels.
[Feedinfo] AquaSaf Shrimp is designed as a comprehensive knowledge package, with in-depth advice and practical measures, plus research from institutions and commercial farms. Will you be adding to this as your work progresses?
[Jean-Benoît Darodes de Tailly] Absolutely! Our objective is to consistently update our package as trials and papers are completed and published. Currently, we're in the process of updating our tilapia whitebook released in 2022.
We have several ongoing projects, primarily focusing on shrimp. We conduct research trials both in controlled lab settings and at farm scale as validating our solutions in real conditions is essential. To date, we have conducted about 25 trials with our solutions on shrimp. We are committed to publishing our findings in peer-reviewed journals and are open to collaborating with researchers interested in our approach. Attention PhD students and post-docs; consider this an invitation!
Our ultimate goal is to promote the broader adoption of fermentation solutions, not only in shrimp farming but also across aquaculture. These functional additives provide many benefits, and we have found that this translates to an observable ROI of between USD$20 and USD$100 per dollar invested.
For more information, see https://phileo-lesaffre.com/en/
Published in association with Phileo by Lesaffre