80 SEPTEMBER • WORLD AQUACULTURE • WWW.WAS.ORG Industry Training and Cultural Shift Farmers, hatchery technicians, and field staff must be trained to understand diagnostics not as “pass/fail” tests but as probabilistic tools. Health management should be proactive and preventative, not reactive. Industry culture must shift from “compliance” to “competence.” Rethinking Nutrition: Balancing Growth, Health, and Sustainability Marine Proteins and Shrimp Physiology Marine proteins such as fishmeal and squid meal provide highly digestible protein, essential amino acids (e.g., methionine, lysine), and immune-boosting compounds (Gatlin et al. 2007). Their reduction or replacement has significant effects on gut health, immunity, and disease resistance (Shakuntala et al. 2022). Not only marine protein sources but also marine lipids such as fish oil and krill oil are increasingly being replaced by plantbased alternatives. This raises an intriguing question: how can carnivorous species adapt to a more herbivorous diet? Risks of Plant-Based Diets While soy, wheat gluten, and corn protein are cost-effective and sustainable, they come with challenges: • Amino acid imbalance: Essential nutrients like taurine are often lacking. • Anti-nutritional factors: These compounds inhibit enzyme activity, damage gut lining, and reduce feed efficiency (Francis et al. 2001). • Palatability issues: Shrimp may reduce feed intake, leading to inconsistent growth. • Poor digestibility: Leads to excess organic waste and pond deterioration. • Contaminants: Plant-based feed ingredients may carry residual pesticides or microbial toxins originating from agricultural sources. These contaminants can compromise shrimp health and pose risks to human food safety. Field reports increasingly associate low-marine protein diets with outbreaks of WFS, EHP, and gut-associated Vibrio diseases. Interpreting Feed Conversion Ratio (FCR) in Context: Distinguishing Real vs. Apparent FCR Most farms report apparent FCR (aFCR), calculated based on feed applied and biomass harvested. This masks chronic mortality and disease-related inefficiencies. Real FCR, based on actual biomass gain, is more accurate but harder to track. In many cases, shrimp die progressively due to EHP or subclinical infections. The surviving population consumes more feed, leading to inflated FCR figures and mistaken assumptions about feed quality or performance. Matching Feed Management to Feed Type Feeds with high plant content require different handling such as slower feeding rates, improved dispersion, and possibly supplemental probiotics or enzymes. Poorly managed feeds result in waste accumulation, higher ammonia, and increased pathogen loads (De Schryver et al. 2008). Proper feed management is not just about cost — it’s a core part of biosecurity. A Call to Align Nutrition, Health, and Biosecurity To address the intertwined challenges of disease, diagnostics, and nutrition, the following actions are recommended: 1. Reevaluate feed standards: At least partial inclusion of marine protein or functional analogs like krill meal, algal meal and others is necessary. 2. Broaden KPIs: Measure survival, immune response, gut health, and waste impact, not just ADG or FCR. 3. Train and educate: Equip farmers with knowledge of nutrientpathogen interactions. 4. Improve reporting systems: Distinguish between feeding FCR and survival-adjusted FCR. 5. Invest in long-term R&D: Conduct challenge trials and microbiome studies to develop feeds that support health and performance simultaneously. Conclusion Shrimp aquaculture has reached a critical juncture. To ensure long-term viability, stakeholders must move beyond narrow efficiency metrics and simplistic biosecurity measures. PCR diagnostics must be integrated with other tools. Broodstock management must emphasize traceability and segregation. Nutrition must be tailored not just for growth but for resilience. Only a science-based, holistic approach can protect the industry from recurring disease cycles and ensure sustainable growth. Notes Dr. Farshad Shishehchian,* Blue Aqua International Pte. Ltd., 31 Kaki Bukit Rd 3 #06-25 Techlink 417818 Singapore; Dr. Wiphada Mitbumrung, Blue Aqua International (Thailand) Co., Ltd., 599/27 Ratchadapisek Road, Jatujak, Bangkok 10900 Thailand; Erika Chong, Blue Aqua International Pte. Ltd., 31 Kaki Bukit Rd 3 #0625 Techlink 417818 Singapore. * Corresponding author: farshad.shishehchian@blueaquaint.com References Chakraborty, R.K. and D.P. Thakur. 2017. Broodstock management PHOTO 4. High quality formulated feed with marine based ingredients. Photo by Nik Siti Zaimah Binti Safiin
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