Global feed production grew by 1.2% in 2024, reaching 1.396 billion tonnes, according to Alltech’s 2025 Agri-Food Outlook. This rebound—an increase of 16.7 million tonnes marks a return to growth after a stagnant 2023, demonstrating the resilience of the global feed industry amid ongoing volatility.

Producers navigated a challenging landscape shaped by disease outbreaks, climate disruptions, and economic uncertainty. Despite these pressures, most regions reported growth. Latin America led with a 3.6% increase, followed by Africa and the Middle East at 5.4%, and Europe at 2.7%. The exception was Asia-Pacific, the world’s largest feed-producing region, which saw a 0.8% decline, a drop of 4.1 million tonnes, driven largely by contractions in China (Table 1).

Despite the decline, Asia-Pacific still accounted for 533.1 million tonnes, or approximately 38% of global feed output. China’s 6.5 million-tonne reduction across pig, dairy, beef, and aquafeeds reflects disease pressures, market oversupply, and ongoing industry consolidation.

The top 10 feed-producing countries remained largely unchanged in 2024 (Table 2), collectively accounting for 65.6% of global feed output, slightly down from 66.0% in 2023. China, the U.S., Brazil, and India represented about 52% of global feed consumption, underscoring their central role in shaping agricultural demand and trends.

Growth in poultry and ruminant sectors, while pig and aquafeed decline

By species, poultry feed remained dominant, making up 42.7% of total feed volume. Pig feed, the second-largest segment at 26.4%, declined by 2.1 million tonnes, continuing its downward trend from 2023. In contrast, the ruminant segment (beef and dairy combined) recorded strong gains, adding 7.4 million tonnes.

Aquafeed, however, declined by 602,000 tonnes, falling from 53.57 million to 52.97 million tonnes, a 1.1% drop year-over-year (Table 3). This marks the second consecutive year of contraction in global aquafeed production.

Regional aquafeed trends:

A mixed outlook

While the global aquafeed market declined overall, regional trends varied significantly (Table 4). Asia-Pacific, still the largest aquafeed-producing region, recorded a 1.7% decrease, driven by environmental disruptions, disease outbreaks, and persistently low fish prices. The shift toward more economical alternatives such as fermented feeds and byproducts, along with challenges in broodstock supply, further contributed to the decline.

Contraction in Latin and North America
Latin America saw a 2.3% contraction, primarily due to new import tax regulations and decreased shrimp feed demand in Ecuador. However, Chile and Peru performed better, aided by favourable environmental conditions such as cooler waters. Government support measures in Brazil and Chile—including feed subsidies and export incentives—may support future recovery.

In North America, aquafeed production declined by 3.7%. Key challenges included sea lice and winter ulcers in salmon farms, coupled with weak shrimp feed demand amid overproduction. Economic difficulties along the U.S. Gulf Coast led to cutbacks, culminating in the early 2025 bankruptcy of the country’s largest shrimp producer, which added further instability to the sector.

Growth in Europe and Africa

Europe stood out with a 2.1% increase, marking its fifth consecutive year of growth. This progress reflects strategic transitions toward sustainability, technological innovation, and robust market conditions. Increased demand for species such as Atlantic salmon, sea bass, and gilthead sea bream, supported by strong international pricing, played a significant role.

Africa experienced a notable 9.1% increase in aquafeed output, albeit from a modest base. This growth reflects increasing adoption of commercial feeds and rising demand for affordable protein sources. In the Middle East, production dipped slightly by 0.6%, though the regional aquaculture industry remains relatively stable.

Oceania recorded the strongest growth rate in 2024, rising by 9.3%. This growth was driven by the launch of new aquaculture ventures and the diversification of farmed species. Government support and proximity to Asia-Pacific markets also contributed to this expansion.

Spotlight on China and Asia’s key markets

Table 5 shows the top 10 aquafeed-producing countries. They accounted for 41.57 million tonnes, representing 78% of global aquafeed production in 2024. Notably, six of these top 10 countries are in Asia, contributing approximately 83% of the total volume among the leading producers, underscoring the region’s vital role in global aquaculture feed output.

China remains the world’s largest aquafeed producer, accounting for roughly 43% of global output. However, its production volume declined in 2024, indicating a broader industry adjustment. Freshwater fish feed—representing about 60% of China’s aquafeed market—was particularly affected by lower market demand and declining prices.

According to recent figures from a Chinese agricultural publication, 44 domestic aquafeed companies exceeded 100,000 tonnes in annual sales in 2024, contributing 17 to 18 million tonnes, around 89% of national production. These companies are categorised into three tiers:

• Tier 1: Companies with over 1 million tonnes in annual sales (Haid, Tongwei, New Hope), producing 8.8 to 9.1 million tonnes (46% of national total), up 4% year-on-year

• Tier 2: Companies producing 500,000 to 1 million tonnes (Yuehai, Evergreen, Aohua), contributing 2.3 to 2.6 million tonnes (13%).

• Tier 3: 38 companies producing between 100,000 and 500,000 tonnes, totalling 5.9 to 6.3 million tonnes

Increases in the Philippines, Vietnam, and India

Several countries within Asia posted mixed results in 2024. The Philippines recorded the highest increase, adding 352,000 tonnes, likely fuelled by strong domestic seafood demand and government support. Vietnam followed with a 140,000-tonne increase, linked to rising export demand for pangasius. India’s aquafeed production grew by 38,000 tonnes, suggesting a continued transition toward compound feed use in carp farming.

Declines in others
Conversely, Bangladesh saw a decline of 17,000 tonnes, due to flood related disruptions, while Indonesia experienced a significant drop of 140,000 tonnes, attributed to disease and environmental challenges (Table 5).

Outlook: Resilience and innovation amid pressure
While the aquafeed market faced declines in several regions in 2024, particularly in China amid ongoing structural adjustments, the long-term outlook remains optimistic. As aquaculture continues to lead global seafood production for human consumption, the sector’s sustainable growth will rely increasingly on the availability and adoption of high-quality compound feeds.

This is evident in the strategic moves by leading Chinese feed companies, which are expanding beyond domestic markets to capture growth opportunities in emerging regions. Rather than signalling weakness, current challenges are prompting greater resilience across the industry, encouraging innovation, and enhancing the sector’s capacity to adapt and grow within a rapidly evolving global landscape.

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A decrease in China’s supply prompts Vietnamese feed producers in North Vietnam to fast-track tilapia farming. An AAP report. 

Prior to 2023, the US implemented substantial tariffs on tilapia imports from China. Tariffs under Section 301 trade actions reached 25%, with an additional 20% introduced earlier this year, resulting in a cumulative rate of 45%. These measures primarily impact frozen fillets, which account for 82% of US tilapia imports. In response to these developments and an increasingly uncertain tilapia trade, Chinese exporters have begun to scale back shipments to the US while seeking opportunities in European and African markets.

Although US per capita tilapia consumption has declined since 2015, the fish is one of the top four seafood choices at 1.04 lbs (0.47 kg) per person. In 2023, the US imported 50,000 tonnes of whole frozen tilapia (80% from China) and 94,000 tonnes of frozen fillets (90% from China). In May 2024, imports of frozen tilapia fillets from China fell by 18%.

Even at the original 25% tariff, tilapia farmers in China were facing hardship. The cost of tilapia production was increasing in China, such that many farmers decided to stop farming. This situation affected the livelihoods of farmers and others in the supply chain (Zhang, 2023).

Vietnam’s tilapia strategy
The Ministry of Agriculture and Rural Development (MARD) of Vietnam, now integrated into the Ministry of Agriculture and Environment, spearheaded this initiative. The 2021 plan targeted a production of 400,000 tonnes of tilapia by 2030, with the objective of establishing tilapia as Vietnam’s second major freshwater export commodity. As a result, Vietnam has been steadily enhancing its tilapia production capabilities and increasing exports of frozen tilapia—both whole and fillet—to the US and other international markets.

Vietnam’s tilapia farmers view China’s reduced supply as an opportunity to access the US market, especially since Vietnamese tilapia previously entered tariff-free before the imposition of new tariffs by the Trump administration. North Vietnam’s tilapia farming methods are influenced by practices in South China. A few livestock feed producers are considering expanding into tilapia feed production and farming in the region.

Tilapia farming in North Vietnam
North Vietnam accounts for a large share of the country’s 30,000ha of tilapia farms and 1.2 million m³ of cage volume. In the provinces around Hanoi, there is the polyculture of black tilapia in ponds with the Chinese carps, while monoculture of red tilapia is in cages in river systems. Heavily involved in livestock feed production and farming, Dabaco Group Joint Stock Company farms red tilapia as well as common carp, channel catfish and sturgeon in 100 cages in the river Duong, Bac Ninh Province.

Tilapia production from 6m x 9m X 3m cages ranges from 5-7 tonnes/cage to 9-10 tonnes/cage. Nguyen Quang Thai, Farm Manager, noted:

“We can raise more fish per cage, but a higher stocking density increases costs because the feed conversion ratio (FCR) rises.”

Production is scheduled for harvests before the Vietnamese New Year (Tết, late January) and in summer. The first crop begins in April, the second in September. Fish are harvested at up to 1kg, with each cycle lasting 10–12 months.

Thai stocks 8,000–10,000 fry (12–15g) per cage, growing them up to 200g in 3 months at 70% survival, then moves them to two cages at 3,500–4,000 fish each. Harvesting is when fish reaches 1 kg, usually over a 10 month cycle. The survival rate is 85%. Production costs USD1.13/kg, with USD1.00 spent on feed.

Streptococcus poses a significant risk during the summer months. Between June and October, temperatures vary from 28 to 29.5°C, which can lead up to 70% mortality. Antibiotics are used as treatment, and in May, the farm reduces stocking density and adds health additives. Other pathogens include Aeromonas and various viruses. Fish are not vaccinated. A notable Streptococcus agalactiae outbreak occurred in 2010 (Dong, 2011). In winter, there is concern regarding the growth of fry to 200g fish.

Feed producer, Viet Nhat Technology Nutrition Joint Stock Company operates two farms – 18ha in Hai Duong and 10ha in Nhan Dinh. Tilapia farming began in 2024, using 4–6ha ponds with depths of 2.2–2.5m. Nguyen Van Dai, Farm Manager and former RIA1 scientist, stocks 7–8 fish/m2 (10–20g each), harvesting 700g fish after four months in summer and 4.5 months in winter. Temperatures range from 36–37°C in summer to as low as 14°C in winter.

Nguyen Dan Ngoc, Nutrition Manager at Viet Nhat, explained that they start feeding fish under 100g with 40% CP feeds, followed by 35% CP feeds for 100-200g fish and then 31-32% CP feeds for larger fish of 300g and above. He reasoned that higher CP feeds are essential for a short culture period to achieve good FCRs.

In his ponds, Dai has paddlewheel aerators. The last harvest was 130 tonnes of tilapia from a 6ha pond. Complete harvesting of the pond takes 7-10 days. Ponds are dried over two weeks to prepare for the next harvest.

“In winter with cooler temperatures, we find that the dorsal meat is better,” said Dai.

In early 2025, farmgate prices were VND29,000/kg (USD1.16). The highest price was VND33,000/kg. In general cost of production is around USD1.00/kg comprising USD0.66/kg for feeds and FCR was 1.3. The land was leased from the government for 20 years and cost VND75 million (USD2,870).

Polyculture of black tilapia
Farmer Tran Van Trang operates five ponds, constructed with cement dykes and soil pond bottoms. Each pond is 3m deep and covers 3,000m2. The polyculture species include black tilapia, common carp, and grass carp, with a total stocking density of 5,000 fish per pond. The stocking ratio is 50% tilapia and 50% carps. Aeration systems consist of long arm aerators, two paddle wheels, and diffusers. Feeding is twice daily using automatic feeders manufactured in China, which are controlled using a smartphone.

The harvest size is 2kg for fillet processing and 1.6kg for live fish markets. The culture duration is 6 months from 15-20g fingerlings. He uses three feed brands (Thang Long, Cargill and CJ) with 30-32% CP feeds and FCR at around 1.2. In winter, he uses probiotics over 3 months together with water treatments.

Bui Dinh Khiem, Nutritionist at Hoa Phat Hung Yen Feedmill said that it wants to expand into aquafeed production. Hoa Phat has two feed mills each in Hung Yen and Dong Nai producing feeds for pig, poultry and layer.

In another farm, owner Pham Van Manh has three ponds of 7,200m2 each with a depth of 2m. The polyculture is also with tilapia, common carp and grass carp at a ratio of 50:50 of tilapia and carps. Some 8,000-tilapia size 250g are stocked and within 5-6 months, fish reach 1.7- 1.8kg. The production is 20-25 tonnes for two crops/year. The farmgate prices for 1.6kg fish was VND37,000/kg in February 2025 and fish are sold live to local markets. His 32% CP feed costs VND430,000/25 kg (USD0.65/kg).

Selective genetics
Some 50% of fry is imported from China and Thailand. In summer, farmers stock fry from Thailand because their genetics selection is considered better suited to disease challenges that occur during the hotter months. The stock sourced from China, which has been selected for rapid growth, is particularly well-suited for the winter cycle. Viet Nhat is planning to start a hatchery.

Farmer Trang, who uses China’s tilapia strain for his March to September crop said that fish with these genetics have a good round body condition factor. There is a size variation in his crop, spreading from 1.2-2kg with an average size of 1.5kg.

Tilapia feeds and feeding
Around Hanoi, several feed mills produce extruded and floating feeds for various fish species. Most feeds are for grass carp, common carp, and tilapia.

“Most of Viet Nhat’s big customers prefer more affordable 28-30% CP feeds since they have good farm practices to ensure consistent production,”

said Ngoc. If farms follow the feed chart suggested by feed millers, it is feeding 40% CP (size 1mm) feeds at the fry and fingerling stages, followed by 35% CP (size 1-2mm) feeds and finally 31-32% CP (size 3-8mm) feeds for larger fish.

Dabaco’s feed plant in Bac Ninh province has a production line of 4 tonnes/hour, supplying floating pellets for species like tilapia, mud carp, catfish and sturgeon. Dabaco has a soybean (SBM) plant and therefore adds SBM at high levels in its carp feeds. However, Le Danh Thanh, Technical Manager as well as aquafeed formulator and responsible for quality control, said that it cannot use more than 40% as the feed price becomes too high. He added that farmers want fish feeds with a stable colour and smell. The farms in the north, contrary to those in the south, prefer the whitish pink colour of red tilapia. In the south, the preference is for reddish fish.

Viet Nhat has a focus on aquafeeds at 15% of its total feed production, which was 240,000 tonnes in 2024. There are two extrusion lines in two factories in Yen My District, North Vietnam and one extrusion line in a factory in the south in Dong Nai. Feed uses 12% distiller’s dried grains with solubles (DDGS) and 20% SBM. The feed mill is modern using robotics for packaging and automation in the plant in Yen My. Formulation is done with a company in China. It produces feeds for both red and black tilapia, snakehead, climbing perch, common carp, grass carp and black carp and channel catfish.

Feeds contribute almost 90% of production cost when FCR is 1.5. Feeds with 30% CP cost USD0.68/kg. When there were import restrictions on meat and bone meal in 2022, Dabaco used DDGS at 13% and now Thanh wants to increase the inclusion rate to 15%. There is also interest to add faba beans into the tilapia and carp feed formulations. Faba beans have been shown to produce firmer flesh but the process of soaking the beans for direct feeding to fish is too laborious. A disadvantage of feeding only faba beans is slower growth.

The print version was published in issue July/August 2025. 

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In November, during the last day of the 5th INFOFISH World Tilapia Trade and Technical Conference & Exhibition 2025 (TILAPIA 2025), held in Bangkok, Thailand, M. Gulam Hussain, signed his book on Tilapia Farming. 

Tilapia Farming: Breeding Plans, Mass Seed Production, and Aquaculture Technologies
provides the latest information on global tilapia farming, hatchery stock breeding, novel aquaculture technologies, feed and fish health management, and food safety and supply chain considerations. Immensely popular for its high nutritional value and low cost of production, tilapia has recently been recognized as the second most farmed fish worldwide. Given the increase in global tilapia production from 369,000 tonnes at the turn of the 21st century to about 6.8 million tonnes in 2020, this book serves as a critically important guide for hatchery operators and aquaculture entrepreneurs.

Written by a leading expert on aquaculture research and development, this book introduces readers to the global tilapia aquaculture industry and delivers key information on general and reproductive biology of tilapia. Early chapters explore brood stock management and the development and operation of mixed sex and monosex commercial tilapia seed production systems, semi-intensive culture systems, and intensive culture systems. Central chapters explore novel tilapia farming technologies, feed and feeding, major diseases, and tilapia health management. Final chapters discuss practical concepts in food safety, processing and trade, and future prospects of the industry.

Tilapia Farming: Breeding Plans, Mass Seed Production, and Aquaculture Technologies
addresses novel information on the latest biological, technological, and supply chain
considerations for tilapia aquaculture. It is an indispensable guide for applied scientists
and aquaculture stakeholders worldwide.

Key Features
• Reviews the global status of tilapia farming
• Covers emerging aquaculture technologies
• Provides guidance on tilapia breeding and stock management, feed and feeding, and disease control
• Offers solutions to microbial hazard management, food safety, processing,
trade, and marketing

Part I: Global Context
1. Introduction
2. Global Tilapia Farming – An Overview
Part II: Biology and Breeding Plans for Tilapia Hatchery Stocks
3. General Biology and Physiology of Tilapia
4. Brood Stock, Replacement, Selection and Breeding Plans for Tilapia Hatchery Stocks
5. Ploidy Manipulation and Production of All-Sterile Female and Male Population
6. Development and Operation of Mixed Sex and Monosex Commercial Tilapia Seed Production Systems
7. Body Color Inheritance and Development of Purebred Strains of Red Tilapia
8. Development and Operation of Semi-Intensive Tilapia Culture Systems
9. Development and Operation of Intensive Tilapia Culture Systems
Part III: Industry Advancements and Future Prospects
10. Novel Tilapia Farming Technologies
11. Tilapia Feeds and Feeding
12. Tilapia Health Management, Major Diseases and Their Control Measures
13. Food Safety and Microbial Hazards in Tilapia Supply Chains
14. Processing, Trade and Marketing of Tilapia
15. Strategies and Prospects of Frontier Development of Tilapia Aquaculture

https://shop.elsevier.com/books/tilapia-farming/hussain/978-0-443-29853-0

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At TARS 2024, Khoo Jia Zin and Alex Lin offer their analysis on RAS as the future of sustainable fish farming. 

Recirculating Aquaculture Systems (RAS) are often touted as the future of sustainable fish farming. By recycling water within a closed system, RAS reduces the need for large water volumes and eliminates many of the environmental concerns associated with conventional aquaculture. However, despite its promise, many RAS farms—particularly in Southeast Asia—struggle or fail due to poor design, species mismatch, and unrealistic
expectations.

The FISH TALK segment at TARS 2024 on Finfish Aquaculture started with presentations on RAS followed by a panel discussion with three second generation industry players; Ariq M. Irsyad, Manager of a marine fish hatchery, 266 Hatchery in Situbondo, Indonesia and two seabass farmers from Thailand, Albert Lai, Vice President, Amazon International Co Ltd in Samutsakorn and Jinnawat Mahalao, Vice President, BoonSawang Farm in, Chachoengsao.

The challenges of RAS
Khoo Jia Zin, Aquaculture Solution Architect at Sepang Today Aquaculture Centre, Malaysia explained that one of the most common reasons RAS systems fail is a fundamental misunderstanding of the engineering principles behind them. Many farms suffer from system failures caused by poor design or inadequate capacity planning (Table 1).

For example, operators may replicate designs without grasping the fluid mechanics that govern water flow, oxygenation, and waste removal. Without proper calculations for head loss, water exchange rates, and turbulent flow dynamics, even the best setups can collapse under pressure.

Another issue is overstocking. Khoo said, “High fish densities, often pursued to boost output, create chronic stress for the fish, compromising immunity and growth rates. Then by adding juveniles or fingerlings carrying latent diseases, this can jeopardise the biological stability of the system. In RAS, a diseased batch can wipe out months of effort due to the enclosed nature of the environment.”

Operational costs
These also pose a barrier. RAS demands substantial capital expenditure and ongoing operating expenses – from pumps and protein skimmers to oxygen systems and biofilters. Many operators oversize their systems in anticipation of future growth, leading to unnecessary energy use and inflated costs. Profitability becomes harder to achieve, when product pricing cannot keep up with these costs, especially in competitive markets dominated by cheaper, conventionally farmed fish.

New innovative solutions rooted in science
Khoo argued that success in RAS is not about adding more technology—it’s about using the right technology, with a deep understanding of both biology and engineering. One of the obvious strategies is narrowing the focus to a specific species. For example, hybrid grouper (Epinephelus fuscoguttatus) has shown superior hardiness and stress resistance, making it a strong candidate for indoor farming systems. However, species like red or golden snapper have proven more sensitive to RAS environments.

Another key solution lies in disease prevention. Enhanced quarantine protocols can result in fingerlings with up to 95% disease-free assurance. Some farms are now experimenting with biofloc technology—where beneficial bacteria form suspended “flocs” that help maintain water quality and reduce ammonia. This method has proven effective in white shrimp (Litopenaeus vannamei) culture and is gaining traction in fish farming as well.

Suspended flocs
Biofloc uses microbial communities to manage water quality and improve feed utilisation in a closed-loop system. The microbial community, primarily bacteria, algae, and other microorganisms, converts products like ammonia and nitrite into biofloc which in turn acts as a food source for the cultured fish or shrimp. This reduces a reliance on external feed and improving feed utilisation.

Khoo also shared that newer farming technologies like Nutricix offer a streamlined, cost-effective approach. Eliminating components like UV sterilisers and pure oxygen chambers, Nutricix reduces both capital and operating expenses. It is a system designed around an optimised autotroph-heterotroph balance, ensuring stable oxygen levels and effective nutrient cycling, even at high stocking densities of up to 50kg/m3.

However, he cautioned that compared with common RAS density, this would be considered as moderate stocking density. (In RAS for salmon it would be at 80 to 120kg/ m3). “I would say that anything over 50kg/m3 for tropical species such as high value grouper would be very risky, since we do not have comprehensive data on indoor farmed grouper. Additionally, there is no complete vaccine data, in contrast to that for the European farmed salmon. For higher stocking density indoor farmed species need good protein for growth and health to overcome the stress factor. In the case for Nutricix, we will continue to gather data on growth rate (stress, diet, selected broodstock) and conduct research on more than just specific pathogen free grouper or other high value species.

Why RAS + IoT is not enough
The integration of IoT in RAS has been great, enabling real-time monitoring of water parameters like pH, ammonia, and oxygen. However, Khoo explained that data collection without corresponding action is meaningless. “If the system is fundamentally incapable of handling biomass loads, no amount of digital readouts will benefit the operation. Worse still, without proactive data use—such as predictive maintenance or machine learning to estimate harvest dates and feed conversion ratios (FCR)—IoT becomes a flashy add-on rather than a performance tool.”

Learning from failures to design for success
According to Khoo, many failures in RAS, particularly in Malaysia and other parts of Asia, often stem from a lack of focus. Many farms try to cultivate multiple species, ignore broodstock management, or ignore the realities of disease control.

In some cases, over investment in unnecessary equipment inflates operational costs without improving outcomes. In others, poor system sizing—either too large or too small—drains resources or limits production.

Yet failure is not the enemy. Khoo says “It’s fine to fail. But we must learn from mistakes.” Success in RAS farming demands a combination of biology expertise, precise engineering, and market awareness. It’s not just about building a system—it’s about understanding your species, knowing your numbers, and matching production with demand. But as indoor aquaculture technologies improve and costs decline, the case for RAS becomes more compelling.

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The focus of this Japan-Thailand joint aquaculture research project is sustainable farming of these two native species.

pecies diversification in aquaculture is vital for a resilient and sustainable food system. Despite some level of species diversity, Thailandâ€s aquaculture production still primarily consists of the Nile tilapia Oreochromis niloticus and Pacific white shrimp Penaeus vannamei. Against this backdrop, the Thai Fish Project—a Japan-Thailand research collaboration titled “Utilisation of Thailand Local Genetic Resources to Develop Novel Farmed Fish for Global Market” was initiated in 2019. 

This project aims to promote the domestication of two native aquatic species in Thailand – the Asian seabass Lates calcarifer and banana shrimp Penaeus merguiensis to advance sustainable aquaculture and food security. This six-year project is funded by Japan International Cooperation Agency (JICA) and Japan Science and Technology Agency (JST). Research activities are jointly led by Tokyo University of Marine Science and Technology (TUMSAT), Thailandâ€s Department of Fisheries, and several other academic institutes from both countries. 

Addressing common challenges
The project has been conducting comprehensive research encompassing various topics to address common challenges in the aquaculture sector. After five years of work, some of the successful achievements include the development of feed formulations tailored for farming the Asian seabass and banana shrimp. The feeds were developed to promote sustainability, improve productivity and create added value within the industry.

Feed formulation for the Asian seabass
The projectâ€s research on feed formulation for the Asian seabass focused on two major objectives:

1) to develop low-fishmeal and low-fish oil feed formulas and
2) to utilise a functional feed additive to enhance the level of docosahexaenoic acid (DHA) in the seabass.

Due to the increasingly unstable global supply of fishmeal and fish oil, which causes price volatility, combined with the resource-intensive production process of catching wild fish to feed farmed fish, it is important to reduce the reliance on fishmeal and fish oil for a sustainable development of aquaculture, particularly for carnivorous species. Therefore, researchers sought to identify suitable alternative protein and lipid sources for seabass and ensure the fish can maintain adequate growth performance.

Low fishmeal and fish oil diets
The project researchers have successfully developed a low-fishmeal and low-fish oil grow-out feed. In this formulation, up to 75% of fishmeal was replaced with various land-based protein sources. According to the research, the alternative protein sources suitable for the fish include soybean meal, Protam protein (bacterial meal), black soldier fly meal, and poultry by-product meal. Meanwhile, the alternative lipid sources are palm and flaxseed oil. These alternative sources have been proven to effectively replace fishmeal and fish oil without affecting the fish growth and biological performance.

In December 2023, the Thai Fish Project organised its first “Seabass Tasting Event” at Centara Grand Ladprao, Bangkok, Thailand. To disseminate the research outcomes, researchers served DHA-enriched seabass sashimi to around 200 participants, including representatives from Japanese business groups in Thailand, who later expressed their interest in sourcing the DHA-enriched Asian seabass. This reflected the market potential of this project.

Enhancing DHA content
To increase the appeal of Asian seabass for both production and consumption, the project focused on adding value to the fish by enhancing its DHA level. With several health benefits of DHA, this project output responded to the growing focus on health and wellness in seafood, directly addressing a crucial aspect of food security which is nutritional quality.

Therefore, after developing formulations with low fishmeal and fish oil diets, the researchers introduced dried Schizochytrium sp. (a marine microalgae species) as a feed additive to boost the DHA content of seabass. A subsequent study proved that feeding Asian seabass with the above-mentioned diets supplemented with 2% dried Schizochytrium sp. for 3 weeks effectively increased the DHA level by 20%, ensuring good growth and sensory properties.

Feed formulation for the banana shrimp
The banana shrimp is popular with consumers, but most of the shrimp available in the Thai market is wild- caught. This is partly due to the limited knowledge and know-how on banana shrimp farming within the country. To effectively promote its farming, the first step is a feed tailored for the species. Feed is key to successful aquaculture by directly affecting the animalâ€s growth and survival.

The primary goal of the projectâ€s research on banana shrimp feed formulation was to develop an artificial feed suitable for each stage in banana shrimp farming. Another goal was to add value to fishery waste by using it as a feed ingredient. Other key research activities included developing a maturation diet for banana shrimp broodstock and utilising marine by-products, such as crab waste- derived chito oligosaccharide and fish hydrolysate, as functional feed ingredients.

While some aspects of the research on banana shrimp feed formulation is still ongoing, researchers have achieved some notable outcomes. One of these is the successful application of marine fish hydrolysate (MFH) in larval diets for banana shrimp.

MFH as an alternative to fishmeal
For some time now, protein hydrolysates have attracted attention as an alternative protein source in aquafeeds, which is as effective and perhaps even richer in other nutrients and is more digestible. The projectâ€s researchers thus attempted to include protein hydrolysates obtained from fish waste into the diet formulation for the banana shrimp. According to research by Krongpong et al. (2021), MFH fermented with Lactobacillus plantarum TISTR No. 541 could replace up to 50% fishmeal and still lead to the highest survival rate and growth in terms of RNA/DNA ratio of the post larvae (PL3).

In this experiment, banana shrimp from mysis 1 (M1) to post larvae (PL3) were fed four diets; a typical shrimp larvae feed (T1), a fishmeal-based diet (T2), a diet with 25% MFH (T3) and a diet with 50% MFH (T4, Table 2).

Overall, the objective of utilising marine fish waste hydrolysate (MFH) as a feed ingredient for banana shrimp has proven to support high productivity farming while promoting the development of a sustainable industry. This approach also helps to reduce reliance on fishmeal and adds value to fish waste.

Next steps
Creating added value and promoting the wise and sustainable use of available resources in Asian seabass and banana shrimp farming through efforts such as utilising black soldier fly meal and fish waste as alternative protein sources for feed, are not the only research focuses of the Thai Fish Project. As mentioned in the introduction, the project covers a range of research topics, with the principal aim of developing a comprehensive aquaculture package for the two target species for Thai farmers.

Under the Thai Fish Project, research topics can be classified into four major outputs: genetic improvement, disease prevention, added value and wise use of resources (as discussed in detail in this article), and preservation of genetic diversity. Based on the projectâ€s timeline, all outputs will be finalised and published by May 2025. More information and future updates can be found on the ‘Thai Fish Project†Facebook page, (https://www.facebook.com/ thaifishproject/?locale=zh_HK&_rdr).

Reference
Krongpong, L., Buathong, T., Foowut, J., and Khongkhuem, N. (2021). Application of marine fish waste protein hydrolysate in banana shrimp (Fenneropanaeus merguiensis, De Man, 1888) larvae diet. In Proceedings of the Annual Conference of Fisheries 2021 pp.178-190. https://anyflip.com/vsjzq/thud/basic

First Published in March/April 2025 AQUA Culture Asia Pacific

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As farmers struggle with low selling prices, there are consequences along the supply chain

By Yufan Zhang

The tilapia was introduced from Vietnam to Guangdong Province in 1957. Today, tilapia is the only exotic fish species to exceed 1 million tonnes. In 2018, its annual output reached 1.8 million tonnes, second only to grass carp, carp and crucian carp, which have been cultured in China for thousands of years. According to the China Fisheries Statistical Yearbook released in 2022, China produced 1.66 million tonnes of tilapia in 2021, surpassing slightly the 2020 production of 1.65 million tonnes.

In 2020, tilapia production in Guangdong reached 740,000 tonnes, accounting for 44% of the national total tilapia production. This could be because the tilapia came first to Guangdong and, coupled with suitable climate and convenient transportation, its production could easily reach this leading position in China.

The two towns of Tonghu and Lilin in Huizhou City, Guangdong Province, have always been the core areas of tilapia farming. Here, there are 2,000ha of fishponds, and the tilapia feed market capacity exceeds 40,000 tonnes. My first market research report was on the fisheries industry in these towns a decade ago. Apart from the bumpy road to the fishponds, a lot has changed.

One couple, 20ha

In the gazebo by the fishpond, 60-year-old farmer Luo and I chatted for a long time before seeing the fish. The sun was too strong at two oâ€clock, and he did not really want to feed the fish at that hour. “It is better to feed the fish later because the water temperature is too high.” He and his wife manage this 20-ha farm.

A 20ha farm is not a small area. If it is just a 2ha shrimp pond, the couple will be busier. This has to do with the fact that tilapia farming has become easier over the years. Tilapia used to be farmed twice a year or even “continuously harvested” following a complex schedule. But now, Huizhou fish farmers follow a single stocking and a single harvesting in a year. Last year, Luoâ€s unit production reached about 2.2 kg/m3, close to the average productivity level. “We cannot raise any more because we cannot sell them. Now, the booking of fish distributors to come and collect the fish often takes half a month, and then they are only willing to buy 2,000kg of fish. During this period, the biomass increases by another 2,000kg,” Luo added, “Some fish in my ponds are from last year and they are more than 3kg already.”

The difficulty with selling the fish also increases the feed conversion ratios (FCR). Over the past few years, the crude protein (CP) content of tilapia feeds has improved from 29% to 33%. If the fish is produced normally without the difficulty of selling, the feed conversion ratio (FCR) can be 1.1. But after keeping the fish in ponds for more than a year and finally selling the stock in the pond, FCR sometimes reaches 1.3-1.4. At present, tilapia feed costs around CNY6,000/tonne (USD841.98), which means that the feed cost is close to CNY8/kg (USD1.12). Then when labour, electricity, pond rental, fish packing and others are included, the production cost will be around CNY1-2/ kg while the selling price/kg of tilapia is about CNY9/kg (USD1.26).

Fortunately, based on the improvement of larvae quality and farming technology, the success rate of tilapia farming is high, at more than 90%. Streptococcus and enteritis are still chronic diseases, especially in the hot season. Once the water temperature is above 30°C, streptococcus outbreaks cause casualties. Many farmers currently use sulfonamides, the fastest way to control the disease. Although, this means a gradual increase in antibiotic resistance.

“For the fish that I sell to factories, I use more non- antibiotic solutions to treat diseases, such as mannan polysaccharides or plant extracts. However, the price of tilapia is very poor this year, and the price of healthcare farm products like immune stimulators is relatively high. When he knew I was writing an article for publication, Luo added the question, “Tilapia farming is hardly a profitable business. Is there a cheaper, non-antibiotic way to treat Streptococcus infections?”

Feed distributor for 20 years

“Luo is my client and he is right. It is difficult for tilapia farmers to make money right now,” said Huang, who has been a feed distributor for more than 20 years and everyone in the area knows his name. He went on to describe some challenges with selling prices.

Currently, there are two very mature marketing channels for tilapia in the market. The first is to sell to a processing plant. Last year, the processing plant bought 0.5-0.6kg fish at about CNY8.6/kg (USD1.20). Margins for the farmer were small, but it is still possible to be profitable with the right farm management. However, this year, due to reduced factory orders the offer price for fish of the same size dropped to CNY7.2/kg (USD1.01).

These prices barely cover feed costs. Farmers lose money for every kg of tilapia they sell to processing plants. The second channel is local markets and supermarkets. Last year, fish larger than 0.7kg could be sold to the local wet market at around CNY12.6/kg (USD1.76). The market requirement has been raised this year and only 0.75kg fish are collected. At the same time, the fish distributor requires that at least 30% of the tilapia in the pond is more than 1kg. But meanwhile, prices dropped to CNY10.6/kg (USD1.48).

“Distribution is so difficult now. You have to book one or two weeks in advance to sell the fish and the fish distributors are taking advantage of the situation.” Huang was also indignant. “But who else to sell it to? It is almost impossible to profit from selling it to a processor.”

Feed distributors and farmers are in the same boat, and when farmers struggle to make a profit, so do they. The number of tilapia farmers in the Lilin and Tonghu areas has decreased by 20% due to continued low profits. I saw many empty fishponds and houses on my way. But the amount of money lent out by feed distributors is increasing.

“Tilapia farmers are not rich. They borrow more than 90% of their feed costs from me. I do not get paid until they sell the fish,” said Huang. As we talked, a young man came over and bought two bags of feed. Huang added, “The debt lasts one year, and over 70% of them owe me over CNY200,000. Currently, the profit margin for distributing tilapia feed is only about 6-7%. We cannot afford to keep up with the debt. Since the beginning of this year, I have stopped giving feed credits to new clients. If they cannot pay cash, I can live without this business. For us and the farmers, this year will be a year of hardship; if the next year still looks like this, I do not know what to do with this business anymore”.

Feed salesmen and second jobs

In the evening, I had a tilapia hotpot with feed salesman Li, who I have known for several years. It is the least we can do for the tilapia industry. During the dinner, he asked me about other job opportunities. “My sales have dropped by more than 30% this year, but my target is still growing. I have not received any bonus for two or three years. Among my friends who entered the market with me, I am the last person holding on. They have either changed careers or are selling shrimp feed. Only shrimp farming is still profitable.” He wants things to change, but it does seem that the poor profitability of tilapia farming in recent years will not change anytime soon.

Recently, farming freshwater fish such as grass carp and common carp have not been profitable either. So, this is not just a problem for tilapia. Production is too overwhelming, exports are lacking, and domestic demand is not strong. These three factors contribute to the dilemma of many freshwater fish farmers.

Feed mills†profitability in fish feed production has been greatly affected. The net profit from one tonne of tilapia feed may not exceed CNY50. This is directly reflected in the feed salesmanâ€s wages. The target sales volume for each feed salesman, once from 5,000 tonnes/person/year, has increased to 10,000 tonnes/person/year. However, the strict KPI system makes feed sales fall instead of rising and increases personnel mobility. Some of the salesmen who did well have even started selling fish for farmers. They also help customers connect to fish distributors, to forge better relationships with customers.

Selling animal health products or farm packs is also a way to supplement their income. That is how we met. In addition to his feed business, he has also sold AQUATE, Alltechâ€s farm pack product for the past few years. This has helped him solve some problems on the farm.

Addressing Streptococcus infections

There are several reasons for frequent tilapia infections. Streptococcus may be the beginning, but in subsequent enteritis, ascites and other secondary symptoms, we often see a variety of pathogenic bacteria infections. Mannan oligosaccharides in Aquate have coagulative and inhibitory effects on various pathogens such as Streptococcus agalactiae and Aeromonas hydrophila.

In an experiment conducted at Kasetsart University, we found that red tilapia treated with AQUATE continuously, in response to challenge stress from Streptococcus and A. hydrophila, has significantly improved the survival rate (Guilherme de Souza Moura et al., 2012). The mechanism behind this also involves the repair of mucosal immune by AQUATE.

A study conducted in China found that feeding ACTIGEN, an important ingredient of Aquate, can repair the gill mucosa and intestinal mucosa of goldfish, and this can even stop the infection of a deadly parasite, Ichthyophthirius multifiliis (Xiaoli Huang et al., 2022). This conclusion has been applied to many companies in China.

The practical application at an eel feed mill showed that the eel gut was significantly thickened, and the number of goblet cells visibly increased due to adding one kg/tonne of Aquate in the feed (Figure 1). Improving the structure of the intestine, as the organ with the largest contact area with the outside environment, will undoubtedly improve the disease resistance of aquatic animals (unpublished data).

A mainstream business

In Chinaâ€s aquaculture market, there are more than 70 commercial species. As one of the few global species, tilapia has a clearer process and pathway from breeding, growing, processing and marketing than many other species. It is correct to say that Chinese farmers can produce tilapia steadily now and in the foreseeable future.

Chinaâ€s tilapia industry is a main street business. Everyone knows their responsibility, and they have known it for years. However, the fish distributing problems faced by farmers, the cash-flow security problems faced by feed distributors, and the profitability problems faced by feed mills are all under unprecedented challenges due to some global problems, such as consumption recession and raw material costs. For a mature species and business model like tilapia, a few branches are off the main street to make a clever detour. The box has been there, so firmly, so certain for so long, making it very difficult to think “out of it”. There may be only two options, forward or backwards. One thing is for sure, it cannot continue like this.

The article was published in issue July/August 2024 AQUA Culture Asia Pacific

The post Tilapia in China: Easy to farm but harder to sell appeared first on Aqua Culture Asia Pacific.

In Suthi Mahalaoâ€s Boonsawang farm, the mark of success is when his seabass is accepted by Japanese chefs in Bangkok

The farm harvests 800g fish and will also harvest 5-6kg fish for special markets such as for the Ikejime preparation. Current farmgate prices are THB120kg (USD3.4) for live fish. For chilled fish, prices (in THB) are 80/kg for 400-600g fish; 90/kg for 700-800g fish; 80/kg for 900g-1kg fish; 70/kg for 1.2-2kg fish and 110/kg for 2.2- 3kg fish. The exchange is THB 9.66 for one USD.

Generally, consumers prefer farmed seabass in sea cages rather than those farmed in earthen ponds, mainly because of off-flavour in pond-raised fish. Boonsawang farm prefers to culture fish in earthen ponds with 15-18ppt salinity. It is also easier to manage because of Suthiâ€s farming experience. He has found ways to address weak points in inland pond culture such as off-flavour, taste, texture, and quality (Figure 1).

Over the last 10 years, Suthi Mahalao has been a happy man. He owns the Boonsawang farm in Bangpakong, Chachengsao Province which has an annual production of more than 700 tonnes of Asian seabass, Lates calcarifer giving a yield of 22.3 tonnes/ha from the 31ha farm. This has been continuous for over 10 years. However, the actual capacity is more than 1,000 tonnes/year, but production has been restricted by demand. Acceptance in high end retail markets is recognition that his seabass production is natural and free of chemicals and antibiotics.

Suthi is not only well known for his farming skills but also as the inventor of a grading bucket now adopted by farmers in Thailand. He has also trained farmers in using pelleted feeds in seabass farming. He is the current chairman of the Thai Marine Fish Farming Association and has received as many as 20 accolades for his contribution to Thailandâ€s aquaculture industry. Among them are Best Fish Farmer in the Royal Ploughing Ceremony Year 2017, Lert Rat Award in 2018 and Best Fish Farmer of the National Bureau of Agricultural Commodity and Food Standards, Thailand.

Marketing seabass

It is well known that the most discerning buyers are Japanese chefs. Success is when inland cultured seabass meets these chefs†criteria on quality and freshness. Boonsawang supplies seabass fillets to premium restaurants in Thailand such as the Kensaku Japanese restaurant and premium Copper Buffet where seabass is prepared as sashimi. The farm also supplies fish for Thai raw fish “Ikejime” (Ikejime is a method of killing fish which maintains the quality of its meat). This was possible as the farmâ€s seabass has passed the test of no off-flavour or muddy taste.

The farming process

The farm starts with 5-inch (12.7cm) fingerlings. Stocking density will depend on target harvest sizes. For harvests of 500g fish, it is 5 fingerlings/m2; for 1 kg fish, it is 3 fingerlings/m2 and for larger fish, it is only 1 fingerling/m2. In general, he says that the stocking density is 3-4kg/m2.

The nursing area is 30% of the farm area and is used for the first month stocking. Fish are disinfected before stocking to be parasite- and pathogen-free. Fingerlings come from a hatchery, which is a member of the Thai Marine Fish Farming Association. Prior to delivery, the hatchery will acclimatise fingerlings to the salinity of pond water at the farm and temperature during transportation is 25-26°C.

Water preparation should be at least a week before stocking. Water is filled to the optimum level and the aerator requirement is 1 HP/tonne of biomass for adequate oxygen demand. The optimum water parameters should be, pH 7.5-8.5, alkalinity >100ppm, transparency 10- 20cm, salinity 15-30ppt, and ammonia nitrite 0. The survival rate is more than 80% for the 6-month cycle. The average daily growth or ADG is around 5.4g.

A leader in seabass farming

Suthi first entered aquaculture in the farming of the monodon shrimp in 1992, as well as acting as a feed distributor. His journey into seabass farming has not been without challenges. In 1995, he began seabass farming using fresh feeds, but he failed. A year later, with the availability of slow sinking feeds, together with another farmer, Suthi continued to farm seabass but again failed. While other farmers left the industry, he persevered with slow sinking pelleted feed, achieving a survival of 20%. He said, “The fish did not look like the seabass but more like a tilapia with a short and plump body. Over the 2 years, I lost USD30,000. I then stopped farming and over the next 8 years, decided to visit farms and learn fish farming from about 300 farmers. In 2004, I restarted, and success came on a yearly basis.”

Secrets of success: Feeding

In a discussion, Suthi identified some techniques which led to his success in seabass farming. It began with him identifying the feeding behaviour of fingerlings and dividing them into five groups. Depending on the feeding behaviour, he will adjust the feeding protocol. In 2004, he was the first farmer to wean 1 inch (2.5 cm) fish onto artificial feeds. He has also modified the feeding rate and management based on fish behaviour i.e., slow and aggressive feeders and those that reject feeds. He has studied the size of feeds required over the culture cycle. The industry uses 4-5 sizes of feeds. Together with Thai Union Feedmill, Suthi has developed 10 sizes of pellets for his farm. The largest size range is 23-30mm.

The broadcasting of feed is in the shape of a traditional Chinese fan with regular speed and force. Feeding is only conducted during low light, i.e., early morning and late afternoon. This is because, according to Suthi, fish are afraid of bright and strong sunlight. He does not use any auto feeder as he wants the feeding team to observe the condition of the fish, understand how to feed and take care of the stock. He also continues to run the aerator during feeding to ensure dissolved oxygen (DO) is sufficient when fish are digesting feed. Attention is on feeding as sometimes fish overconsume when they are stressed.

In general, the feeding protocol includes no feeding over the 2 days after stocking and on the third day, they are fed only for the morning meal. Feeding is within the feeding frame with a blue net with a perimeter of 50m. Broadcasting of feed is aligned to the wind direction and is completed within 10 minutes. Feed amount is 90% of feed demand according to biomass. The team dissects fish and examines left over feed in the fish stomach, identifies sizes of pellets and adjusts feeding accordingly. Some feed conversion ratios (FCR) are shown in Table 1.

At the heart is pond preparation

Suthi has studied in detail soil and water parameters and their management so that he can operate the farm successfully with the principle of “prevention is better than cure.” His technique of pond preparation is a mechanical way of using only water. This is essential so that fish cultured in these ponds have no off-flavour. This is done by switching between dry and wet soil conditions multiple times to eliminate bacteria, snails or weeds and use chain dragging to refresh the pond bottom.

Pond preparation is over 50 days and starts with drying the pond after harvesting until the pond bottom cracks. The pond is then filled with water to a depth of 60cm in the deepest part of the pond. Aeration is for 2 days using a long arm aerator and with 10 dosages of effective microorganisms (Bacillus probiotics) which is also used during the culture period.

Next is chain dragging continuously over 20 days. This is done twice a day, each for 2-3 hours per round during the early morning and evening. This is to stir up all the sediments and mix them with water. According to Suthi, on day 3, toxic gases will burst out creating a stinky, black, and oily surface and on day 7-10, there will be more gas emissions. On day 11-12, the water colour will change from black to gray and by day 15-17, brown bubbles will surface. If this does not happen, it is time to add microorganisms.

From day 18-20, the farmer should examine the soil to ensure cleanliness. Chain dragging is repeated if there is still black soil. Drying will follow until the soil cracks on day 21-22. He cautioned that it may be necessary to repeat chain dragging or extend the process, if at the last crop, there were parasites. Next is to apply lime at around 400- 500kg/acre (1,000-1,235kg/ha), followed by spraying with water and leaving overnight to reduce the bacteria population. Water is then added very slowly to fill up the pond and to cover only 10cm in the shallow area.

Final words

Suthi said, “Inland farming can be better once the farmer learns how to manage the farm properly. What we need is knowledge and know-how. I am always happy to share my experiences and knowledge with anyone with a passion to learn. I love farming fish and sharing what I learnt is important for me.”

“To feed the world with farm seafood is becoming more important and a farmer must value his or her contribution. It is essential to feed our fellow human beings with safe and quality fish. This is our responsibility.”

The article was published in issue Marxh/April 2024 AQUA Culture Asia Pacific

The post A success story on Thai earthen pond seabass farming appeared first on Aqua Culture Asia Pacific.

LST in Chachoengsao Province has an ambitious plan for genetic improvement of the Thai strain after developing SPF broodstock and hatchery rearing for high survival and uniform all-male post larvae

By Zuridah Merican

Lukkungsetthi Company, or LST, in Amphoe Ban Pho, Chachoengsao Province, is the only broodstock multiplication centre and hatchery in Thailand able to consistently supply all-male giant freshwater prawn Macrobrachium rosenbergii post larvae for grow-out farms. At the AIT-organised international conference on the giant freshwater prawn, Giant Prawn 2023 (GP2023), in November, Somprasong Natetip, LST Founder and Director, described his journey since 2017. Next is to expand on his closed biosecure system for the genetic improvement of the Thai strain of this crustacean in terms of phenotype.

In Thailand, similar to other Southeast Asian countries, the giant freshwater prawn sector faces issues with supply of post larvae due to several failings, either because the larvae do not reach post larvae stages or there is a delay. Common too are the non-uniformity in post larvae size, low survival rates and incidences of white tail disease.

Challenges in grow-out ponds

Grow-out using the conventional post larvae will result in different proportions of the morphotypic stages of the male prawn: 5% blue claw, 20% strong orange claw and orange claw and 25% small males. Some 50% of the population are females, which grow slower than male prawns. This combination usually results in growth by hierarchy behaviour, low survival rates, slow growth and low average daily growth, high feed conversion ratios (FCR) and more females with lower growth rates than males. Some of these have poor market prices. Khun Somprasong also added that there is a demand for prawns with big tails, short heads and small and orange claws in Thailand.

Consequently, farming an all-male population is preferred. Males generally exhibit faster growth rates and are 2–3 times bigger and heavier than females of similar age. The traditional practice is manually selecting males for culture during the grow-out, but it is labour-intensive and generally unsuccessful in producing an all male prawn monoculture.

Commercialisation of all-male technology in Thailand

In 2006, Dr Wikrom Rungsin at the Department of Zoology, Faculty of Science, Kasetsart University, developed the technology to produce all males of the Thai strain of M. rosenbergii using a neo-female technology. This is ablation of the androgenic gland in 45-day post larvae (PL45). The androgenic gland is essential for sexual differentiation in prawns and the development of male primary and secondary sexual characteristics (Tan et al., 2020). Done at the right time, this delicate procedure causes the post larvae to develop into neo-females with chromosomes ZZ. Neo-females are mated with local males to produce all-male progeny theoretically. Neo-females are males functioning fully as females.

As part of the “Talent Mobility” program of Kasetsart University, National Science Technology and Innovation Office of Thailand, LST is commercialising this technology. Dr Wikrom acts as a consultant at LST. Following a market survey and developing a vision for the freshwater prawn hatchery segment in Thailand, the company developed a prototype hatchery in 2017. However, for Khun Somprasong, it was not just adopting the process. It was more to do with the genetic improvement of the species.

It has developed closed biosecure systems for a breeding program, targeting the production of fast-growing all-male post larvae from specific pathogen-free (SPF) broodstock. Since 2019, LST has a nucleus centre comprising separate facilities for quarantine, maturation, spawning and genetics selection and breeding. Then, there is a broodstock multiplication centre and hatchery. Nursery and grow-out ponds complement these facilities to conduct field trials.

Samples were collected as founder stocks. One might think that large broodstock are required for good post larvae, but Khun Somprasong said, “It is only necessary to have a broodstock, even though small, which has been through the reproduction process until fertility is complete.”

The criteria for SPF status required assurance of the absence of 5 major pathogens over a two-year period. These included white spot syndrome virus (WSSV), yellow head virus (YHV), Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV), both causative pathogens for white tail disease. There is also the monitoring for decapod iridescent virus 1 (DIV1) which has not been recorded in Thailand but is on the Department of Fisheries Thailand (DOF) monitoring list. “We cannot use live feeds for broodstock maturation to prevent contamination from pathogens,” said Khun Somprasong.

Essentially, the game changer for Thailandâ€s M. rosenbergii industry is the closed biosecure facilities to keep pathogens away and control rearing conditions.

Quality and uniform post larvae production

During a post-conference visit for GP2023 participants, LST hatchery staff explained some practices. At the pre- spawning stage, each male and female broodstock is held in one cubicle. In the mating tank, there is one male to 10 females. After moulting, prawns will mate very quickly; within a 15-minute interval, the females will allow entry of spermatozoa. Following hatching, nauplii are transferred into the closed indoor hatchery.

“We have developed the precise standard operating procedures to mass produce post larvae. We are proud that we can harvest nauplii daily, reach the post larvae stage in 14-15 days and complete in 4 days much faster than conventional post larvae produced with undomesticated broodstock. Our post larvae are of uniform sizes without going through a selection process. Post larvae are pathogen-free, and for every batch, larvae develop to post larvae well. We do not need to use antibiotics,” said Khun Somprasong.

In the hatchery, there is a well-controlled feeding regime. LST produces its own pathogen-free instar 1 artemia (500µ) which can be kept in ice for 48 hours. The first feeding of nauplii is with this artemia at 100g/million nauplii. In later weeks, larvae are fed egg custard (300µ) with added astaxanthin and artemia, alternated at specific intervals to prevent water pollution. The hatchery team discussed the sources of artemia available in Thailand with participants and their pros and cons. They also indicated that when using GSL artemia, each gram contains 250,000 to 260,000 cysts.

Post larvae are fed pelleted feeds. After PCR testing (PL4), they are sold to farmers and cultured in nursery ponds to gather growth performance data as feedback for the genetic improvement work.

Success rate in an all-male production

In the case of LST, the current success ratio is > 90% male progeny. In his presentation, Khun Somprasong showed how for some post larvae the delicate ablation procedures can fail, indicated by a white shadow in the gland of the head (Figure 1).

“In the pond, one can find this combination: >90% males, higher survival rates, fast growth with low FCR and ultimately higher profit margins with lower costs of production.”

Nursery and pond grow-out

Harvests at nursery level and grow-out ponds justified the progress with LSTâ€s post larvae. In Table 1, Khun Somprasong explained the growth of PL4 in outdoor nursery ponds compared with conventional stocks of post larvae available in Thailand. While LSTâ€s stocks grew to size 120-125/kg, conventional stocks grew 34% slower to reach only size 170-200/kg after 60 days when stocked at 19 PL/ ha (Table 1)

Field trials

Khun Somprasong described experiences in the field in the monoculture of his post larvae. This started with a nursery phase of 2 months to grow to 4g or 200-300 juveniles/kg. In the grow-out phase, the stocking was 7,000 to 10,000 juveniles/rai (1600m2). This translated to 5-6 juveniles/ m2. At days of culture (DOC) of 80-100 days, and after three times culling, the production totalled >2 tonnes/ha. (Related article: Polyculture of vannamei shrimp and giant freshwater prawn in Chachoengsao Province pages 22-23)

Into the future

In 2020, LST worked on increasing production, from 50 million post larvae in 2017 to 300 million post larvae in 2020. In 2021, in cooperation with Kasetsart University, the plans included building up more farms. Khun Somprasong is now looking at a corporate image for the company, increasing production and reducing production costs, in parallel to developing a full-fledged genetic centre for Thailandâ€s M. rosenbergii and investing around THB 100 million (USD 2.85 million). It already has the permit from DOF to export post larvae. Meanwhile, the R&D cooperation with Kasetsart and NRTC will continue.

References:

Kianann Tan, Huigong Jiang, Donghuo Jiang, Weimin Wang, Sex reversal and the androgenic gland (AG) in Macrobrachium rosenbergii: A review, Aquaculture and Fisheries, Volume 5, Issue 6, 2020, 283-288, https://doi.org/10.1016/j.aaf.2019.11.004.

Wikrom Rungsin, Natthapong Paankhao, Uthairat Na-Nakorn. 2006. Production of all-male stock by neo-female technology of the Thai strain of freshwater prawn, Macrobrachium rosenbergii. Aquaculture, Volume 259, Issues 1–4, 2006, 88-94, https://doi.org/10.1016/j.aquaculture.2006.05.041.

Somprasong Natetip, Intensive all-male prawn seed production in closed system commercial success of an improved giant prawn strain in Thailand. Presented at Giant Prawn 2023, November 27- 29, Bangkok, Thailand.

The article was published in issue January/February2024 AQUA Culture Asia Pacific

The post Commercial production of all-male giant freshwater prawn post larvae in Thailand appeared first on Aqua Culture Asia Pacific.

Post pandemic, industry is optimistic on the potential growth of this fish

By Zhang Yufan and Henry Wong

A largemouth bass grow-out pond in Foshan, Guangdong.

China, often referred to as the global aquaculturepowerhouse, boasts the farming of the most extensivearray of aquatic species. Its aquaculture industry issynonymous with the culture of the “four major carp” fish,collectively known as Asian carps, which account for abouthalf of Chinaâ€s aquaculture production in terms of volume.

A Rising Star

The largemouth bass, affectionately referred to as the‘California bass†in China, has made a remarkable leap in production, emerging as the next major freshwater cultured fish after the Asian carps. The largemouth bass consumption market primarily thrives in tier one and two cities, harbouring considerable potential for market expansion.

The growth of large mouth seabass in China

The largemouth bass (Micropterus salmoides), originally from North America, was introduced to mainland China in1983. Over the past 30 years, the industry has fine-tuned its operations, creating a complete supply chain from seed production to marketing.

A storage room for largemouth bass feed

Data from the Chinese Fishery Yearbook showed its production increasing from 457,000 tonnes in 2017 to 802,000 tonnes in 2022. The main aquaculture regions are in Guangdong, Zhejiang, Jiangsu, Hunan and Sichuan provinces. In 2022, the total aquaculture production in these top five provinces was approximately 685,000 tonnes, accounting for 85% of the national total, with Guangdong alone contributing about 382,000 tonnes or48% of the national total.

Largemouth bass feeding on the water surface.

Pond culture in Guangdong

Pond culture is the most prevalent, particularly inGuangdong province. The sizes of ponds typically range from 2,000 to 3,500m2with water depths of 1.5 to 2.0m.Stocking densities in ponds are approximately 4,000to 10,000 juveniles (8-10cm) per 1,000m2. In the past, largemouth bass in China were primarily fed frozen trash fish during their growth phase, yielding a feed conversion ratio (FCR) exceeding 4.0 but its farming was still profitable.

Since 2017, the government has discouraged feeding of frozen trash fish in aquaculture, leading to the development of commercial pelleted feeds. FCR improved to 1.1-1.3.Commonly, largemouth bass extruded feeds have 44-48% crude protein. The use of such feeds in farming requiresless labour, improves water quality and reduces risks of diseases.

Price seasonality and profitability

Price fluctuations over the past five years reveal significant seasonality in the market for largemouth bass. Prices remain steady from January to April each year and steadily rising from May to August to reach their annual peak. In October, prices undergo a decline due to an increase of supply at year-end. The decline continues into the beginning of the following year.

The recorded best profit occurred in August 2019, reaching an impressive RMB14.8/500g (USD4.06/kg). In 2022, increases in production costs related to feed ingredients, pond rentals and labour resulted in a production cost increase of RMB1-1.50/500g (USD0.27-0.41/kg) compared to the previous year. In Guangdong, rearing the first crop incurred a cost of approximately RMB9-11.5/500g (USD2.46-3.14/kg). However, the farm gate price showed a nearly RMB1/500g (USD 0.27/kg) year-on-year decrease, reducing the average profitability of largemouth bass farming in 2022 by an estimated RMB1-2/500g (USD0.27-0.54/kg).

In 2023, the largemouth bass industry encountered an unexpected price collapse and caught many farmers off guard. The average price of largemouth bass in major producing areas was approximately RMB12.8/500g(USD3.51/kg), with some areas, such as in Foshan (Guangdong Province), seeing historic lows of RMB11/500g or USD3.0/kg (October, www.fishfirst.cn). High pond rental costs, expensive feed and low fish prices prompted many farmers to reconsider restocking and farming.

A farmer manually broadcasting feed to largemouth bass.

To gain insight into the situation, the authors visited Mr Chen, a pioneer of largemouth bass farming in China. He attributed the price decline to an oversaturated market, noting that the industry had grown significantly over the years, 2017 to 2019. This expansion, combined with the industryâ€s reliance on credit sales and private lending, placed immense pressure on the entire supply chain, affecting farmers, feed distributors and raw material suppliers. As a result, some farmers hesitated to sell their fish due to poor prices, and the ongoing decline in fish prices since August exacerbated financial difficulties of farmers across the industry.

Challenges

The industry has long grappled with disease-related challenges, which have intensified this year due to increases in stocking density. During the larval stage, splenorenal necrosis virus outbreaks often result in the mortality of over50% of larvae. Iridoviridae viruses are also prevalent and their uncontrolled presence in the middle and late stages offish farming can lead to mortality rates of around 15-20%.

Feed, constituting 70% of farming costs, accounted for both cost and nutritional issues. In 2018, a tonne of large mouth bass feed cost around RMB11,000 /tonne(USD1503), with a feed conversion ratio (FCR) of close to1.05. Presently, feed prices have surged to RMB13,000/tonne (USD1785.50) while the FCR has exceeded 1.2. Additionally, nutritional problems were intertwined with diseases, leading to the rising occurrences of pale liver and pericardial congestion. These multi challenges pose diagnostic and treatment complexities. Furthermore, there have been reports on the yellow flesh of largemouth bass, rendering them unmarketable.

New developments in nutrition

Initially, the nutrition of largemouth bass was primarily focussed on macro nutrients, particularly protein, amino acids, lipids and carbohydrate digestibility, aiming to replace frozen trash fish in their diet. However, recent scientific advancements have shifted the focus towards micronutrient studies, specifically vitamins and minerals.

The Guangdong Academy of Agricultural Sciences in China made a significant discovery, revealing that incorporating selenium yeast (Alltech Sel-plex) in the feed substantially enhanced the antioxidant capacity of largemouth bass haemocytes and reduced apoptotic cell counts. This form of selenium also proved more efficient in accumulating selenium in fish muscle compared to inorganic selenium (Xu et al., 2023). Another study by Sun Yat-sen University showed that substituting inorganic zinc with zinc proteinate in largemouth bass feed improved their growth performance. The optimal dosage of peptide zinc, at just60ppm, was significantly lower than the industryâ€s usage of inorganic zinc. This low-dosage, high-efficiency zinc source enhanced largemouth bass†overall antioxidant capacity and muscle quality (He et al., 2023).

Conclusion

Although the farming of largemouth bass still faces many challenges, it is important to remember that this is just apart of its farming development. With the right approach and continued dedication, the industry is poised to rebound. Market factors, including the lower demand caused by the post-pandemic recovery and increased feed costs, have undoubtedly changed the supply and demand curve.

Optimism is warranted for the potential future growth of this species. With advancements in genetics, precision nutrition and a growing market acceptance for largemouth bass, the culture of this species will take a turn for the better. It is a testament to the resilience and adaptability of aquaculture, and it reinforces the industryâ€s ability to overcome challenges and thrive in the face of adversity.

Authors:  

Dr Henry Wong is Commercial Development Director, Asia Aquaculture, Alltech. 
Dr Yufan Zhang is China Aqua Business Development Manager Alltech China.

This article was published in the print edition of Aqua Culture Asia Pacific in November/December 2023.

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A by chance hybridisation is now in generation 4 and is moving towards commercialisation

By  Joe Ng

In land scarce Singapore, it is imperative to develop or source new species of fish that are suitable for our local industry players and where farms can easily increase production capacity just by moving further out to sea. There will be less competition for land and freshwater resources, allowing these for national development/urbanisation.

Century Aquaculture was set up in 2017 to research on types/species of tilapia suitable to acclimatise from fresh to seawater. The aim is to farm marine tilapia Oreochromis spp successfully in our local waters. We hope our efforts will help and contribute to Singaporeâ€s food security goals for 2030. It will also give our local fish farmers a better option and move away from either farming the low value milkfish Chanos chanos in waters off Lim Chu Kang or of the high value grouper or snapper (Epinephelus spp or Lutjanus spp) in waters off Changi. Additionally, we believe that we need a fish that offers an affordable source of protein for Singaporeans.

Fish farmers in Singapore have always faced stiff price pressures from farms in neighbouring countries such as Malaysia and Indonesia, where the cost of production is considerably lower than that in Singapore. Therefore, we needed to find ways to be more competitive, at least in supplying our domestic market.

There is a good local demand for the marine tilapia in Singapore. Consumers have accepted that tilapia farmed in seawater tastes better and is unique to the Singapore market. We believe that developing marine
tilapia will not only help starve off price competition from neighbouring countries, but also offer better prospects for our coastal farms.

Developing a unique marine tilapia strain

In 2018, we embarked on a journey to search for a suitable strain of tilapia, with the assistance from two partners, trained tilapia and pangasius farming at the Asian Institute of Technology (AIT) in Bangkok, Thailand. We leased a small farm for this research and adopted the latest hatchery practices from AIT. Coincidently, when we took over the farm, we also “inherited” about 100 jade perch Scortum barcoo from the previous operator.

Some strains of tilapia that hatcheries claim can tolerate high salinity (30ppt) were tested. We stocked the fingerlings in open seawater cages off Lim Chu Kang but none survived. Most of the mortality was during the high tides, occurring every fortnight and fingerlings struggled to adapt to strong water currents. These were less than ideal water conditions with large fluctuations in salinity and temperature.

Tasty jade perch

Meanwhile, we tasted the jade perch that we had inherited. They were excellent whether steamed, grilled, baked or pan fried. Furthermore, although omnivorous, the jade perch is extraordinarily high in omega-3 fatty acids. We decided that we should produce fingerlings for the local market with assistance from the Singapore Food Agency (SFA).

After several failed attempts with different sources of tilapia, the farm decided to acclimatise the jade perch since some studies reported that it can tolerate salinities up to 30ppt. However, after numerous attempts, the conclusion was that once we reached a salinity of 18ppt, the fish could not survive. In 2019, I did the unthinkable by trying to cross breed tilapia and jade perch although biologically it would not happen since they are two completely different species of fish and the only shared similarity is that both are freshwater fish. Another assumption was that if breeding was successful, offspring would most likely be sterile.

Hybridisation of tilapia and jade perch

After a long wait of about 2 months, we produced the first batch (F1) of hybrids. However, the fingerlings (F1) were odd in terms of shape and colour. Nevertheless, we continued to get a batch of F1 fish every other month. This was the start of our hybridisation program in 2020. We spent the next two years studying and documenting this process.

Currently, we have the 4th generation of the hybrid and a few hundred female broodstock to move to the commercialisation stage (pending regulatory approval). Below are the findings that we have documented over the past 2 years.

Appearance
It was apparent that the tilapia genes were dominant as the first and second generation hybrids look very much like the tilapia. There are variants in colour: orange, black and silver. The 4th generation is taking more of a hybrid shape, presumably as the gene stabilises.

Characteristics of the hybrid
This is where we noticed marked differences from the tilapia: 
a. Male to female ratio was 95% to 5% (similar to jade perch)
b. Egg production was more than 3000. This was the maximum based on current observation for a 200g female.
c. Adaptation to salinity is from 0 to 38ppt, which means that the hybrid can be farmed in both freshwater and full seawater. Fingerlings can also tolerate rapid increases in salinity from 0 – 35ppt within a week.
d. Growth of a 2-inch (5.1cm) fingerling to 450g is 5 months, based on a current open sea cage trial.
e. Flesh is firm and sweet with no muddy off flavour. This is similar to jade perch which consumers say tastes better than the red snapper.
f. Survival rates have been recorded at 98% in cement tanks.
g. Survival for swim outs is 95% indicating the ability to feed on artificial diets.
h. Survival in extreme conditions was evaluated with the following parameters – high stocking density using 2-inch (5.1cm) fingerlings at 25kg/m3 in 25ppt seawater (Table 1).

A preliminary test conducted by Republic Polytechnic, Singapore, in October 2022, showed that the hybrid is a 90% crossbreed. It is waiting for grants to run a full test on the fish.

Based on the above findings, we believe that the potential of this hybrid is enormous. The hybrid is not only a very hardy fish, but very economical to farm. Feeds for the tilapia will suffice to achieve good growth. With rapid urbanisation in many countries and also the pressing need to feed the growing world population, this fish might an alternative for marine farms.

More to uncover
Currently, we are conducting tests on the hybrid to determine whether it has a higher resistance against diseases that are affecting the tilapia. Theoretically, if there is a change in chromosomes (new genes from jade perch) there should be a higher resistance or immunity against common tilapia diseases. However, there is a lack of information on the jade perch since it is still not a widely farmed fish. I attribute the robustness characteristic of the hybrid to the introduction of jade perch genes. If this can be proven, the hybrid can be cross bred with popular strains of farmed tilapia to provide a “natural vaccine” for stronger resistance or immunity.

Next steps
Today, we are still in the process of selection for the broodstock to enable us to achieve a certain level of consistency in terms of shape and colour. We hope to accomplish this by the first half of 2023. There is still much to uncover on this new hybrid and whether all that we have achieved is scientifically acceptable. If so, we would like to be recognised that this achievement is probably the first of its kind in the world.

Note: This article was published in issue Jan/Feb 2023. In July 2023, Joe updated on the FB of Centyry Aquaculture. 

Our fish is indeed a cross between Jade Perch and Tilapia, making it a completely new species and to our knowledge, it could be one of its in the WORLD!!! 

Following the publication of our article on the Hybrid Fish (Jade Perch x Tilapia), there were many enquiries and discussions amongst acedamics and industry players with most are quite skeptical over the initial tests done by Republic Poly and claimed that the test are inconclusive (though most evidence suggest that it is)

Although it is a very rare occurance but studies suggest that it is still a possiblity. We persevered and sought help to coduct a nuclear gene test on the fish and the result is positive and CONCLUSIVE

“Now we have scientific evidence to support our claim that our fish is indeed a new species, we named it Xin Sea Perch (新海鲈), as it was created, discovered and researched in Singapore (The Singapore Fish)”

Xin Sea Perch is highly versatile (can be farm in sea or fresh water) and hardy, it has high aquaculture potential, making it an extremely good food fish to farm and a potential game changer in the global aquaculture industry

Recently, we have conducted private food tasting for the fish, whether it is steam, grilled, panfried or sashimi, it passed with flying colours. Its meat texture and quality is very close to Jade perch…..firm and sweet!!!

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