The overuse of antibiotics in livestock and aquaculture has become one of the greatest threats to human and environmental health.

📈 Antibiotic use in terrestrial animals is projected to grow by over 60% between 2010 and 2030.

⚡This overuse of antibiotics is accelerating the development of antimicrobial resistances

⚠️ Antimicrobial resistance already kills 700,000 people every year, a number that could rise to 10 million annually by 2050!

🔴 Antibiotic excessive use also affects soil microorganisms, plants (↘ photosynthesis) and water organisms.

This is not just a veterinary issue. It’s a strong concern for public and environmental health...

At Mandible, we explore how insect-based ingredients can provide part of the solution as they contain

1️⃣ Antimicrobial peptides: natural molecules that destroy harmful bacteria cell membrane (examples: defensin, cecropin, attacin, sarcotoxin). More than 150 have already been identified in insects!

2️⃣ Lauric acid (up to 60% of fatty acids in black soldier fly larvae: a fatty acid with strong antibacterial properties. It destabilizes bacterial cell membranes (becoming permeable), inhibits membrane exchange and energy metabolism. Bacteria are unlikely to acquire resistance!

3️⃣ Chitin & chitosan: components of insect exoskeletons that disrupt pathogenic bacteria. It reacts with bacteria cell membranes and damages them. It can however degrade feed digestibility if supplied to farmed animals…

Beyond direct antimicrobial effects, insect products also strengthen animal immunity, notably

✅ Shaping gut microbiome toward beneficial species

✅ Reducing inflammation

✅ Improving mucosal defenses (gut and fish skin) and immune cell proliferation (lymphocytes and leukocytes)

Proven results observed in

🐟 Nile tilapia, rainbow trout, Siberian sturgeon, common carp

🐦 Chicken, turkey

🐖 Pig, rabbit

👉 This means healthier animals, reduced antibiotic use, and less risk of antimicrobial resistance spreading into our food systems, soils, and waters.

📣 The take-home message is clear:

⚕️Insect farming isn’t just about sustainable protein. It could also become a critical tool in safeguarding public health!

When we talk fertilizer, the conversation usually stops at NPK. But in tropical agriculture, secondary and micronutrients often make the difference between “average” and “exceptional” yields.

📉 The Hidden Problem in Tropical Soils

• Weathered soils in Malaysia and across Southeast Asia are acidic and low in cation exchange capacity (CEC).

• Leaching & fixation mean nutrients like boron (B), zinc (Zn), and magnesium (Mg) don’t stay available for long.

• Continuous high-yield cropping removes these nutrients faster than they are replenished.
  
  

🔬 Critical Secondary Macro and Micronutrients in the Tropics

• Boron (B): Essential for pollen tube growth and fruit set (oil palm, durian, papaya). Deficiency = poor fruiting and bunch abortion.

• Zinc (Zn): Required for enzyme activity and hormone regulation. Deficiency in rice causes stunting and bronzing.

• Magnesium (Mg): Core of chlorophyll. Deficiency = interveinal chlorosis, common in oil palm on sandy soils.

• Sulphur (S): Needed for amino acids. Deficiency increasingly common as atmospheric deposition drops (post-clean air policies).

• Copper (Cu), Manganese (Mn), Iron (Fe): Key in photosynthesis and disease resistance, often tied up in low pH soils.
  
  

⚖️ Economic and Agronomic Payoff

• A small addition of B or Zn can increase oil palm yields by 10–15%.

• Correcting Mg deficiency improves photosynthesis efficiency and fresh fruit bunch weight.
  
  

• In rice, Zn fertilization reduces “hidden hunger” in both crops and consumers (biofortification effect).
  
  

🌍 Management Approaches

1. Soil & leaf analysis — diagnose before applying.

2. Targeted applications — foliar sprays for rapid correction, soil application for long-term balance.
   Blended fertilizers — NPK with secondary/micronutrient enrichment.

3. Organic matter & frass inputs — improve nutrient retention and feed beneficial microbes that mobilize micronutrients.
   
   

👉 Takeaway:
In the tropics, chasing yields with just NPK is like trying to run a marathon on fast food: you’ll finish, but not in peak form. A balanced diet for crops means paying attention to the small nutrients with big impacts.

The future of tropical agronomy isn’t just about more nitrogen, phosphorus, or potassium. It’s about precision nutrition, including the forgotten players.

🌱 Fertilizer Use Efficiency in the Tropics: Science Behind Smarter Inputs

In Malaysia and other humid tropics, fertilizer use efficiency is often below 50% for nitrogen (N), <20% for phosphorus (P), and variable for potassium (K). The rest? Lost to the environment.

Why efficiency is low in tropical systems:

• 🌧 High rainfall & leaching: Nitrate-N and K⁺ are flushed below the root zone.

• 🔥 High temperature & volatilization: Surface-applied urea can lose up to 40% of N as NH₃ gas.

• 🧪 Acidic soils & fixation: Strongly weathered soils bind phosphorus onto Fe/Al oxides, making it unavailable.

🔬 Strategies for higher Fertilizer Use Efficiency (FUE):

• Source × Rate × Time × Place (4R Nutrient Stewardship)
  
  

  • Urease or nitrification inhibitors reduce N losses by 30–50%.

  • Controlled-release or slow-release fertilizers (polymer/sulfur coated) synchronize supply with crop uptake.

  • Split application aligned with growth stages (e.g. oil palm’s vegetative growth, rice tillering).
    
    

• Soil Amendments & Chemistry
  
  

  • Liming reduces P fixation and improves base saturation.

  • Liming can supply Ca²⁺ and S while improving soil structure.

  • Organic matter inputs enhance soil structure in degraded or nutrient-poor soils
    
    

• Microbiome Management
  
  

  • N-fixers: Free-living diazotrophs (Azospirillum, Gluconacetobacter) can supplement N in oil palm and rice systems.

  • P-solubilizers: Bacteria (e.g. Bacillus, Pseudomonas) and fungi mobilize phosphate bound to Fe/Al oxides.

  • Mycorrhizal fungi: Expand root absorptive surface area, improving uptake of immobile nutrients like P and Zn.

  • Organic matter inputs: Supports beneficial microbial communities that recycle nutrients and suppress pathogens.
    
    

• Precision Diagnostics
  
  

  • Leaf nutrient analysis (e.g., oil palm frond #17) guides targeted applications.

  • IoT-enabled soil and water sensors give real-time nutrient status for paddy and vegetables.
    
    

⚖️ The Payoff

• Economics: Reduced fertilizer bills and higher return on input costs.

• Yield: Stronger root systems, better nutrient synchronization, and reduced deficiency symptoms.

Environment: Less nutrient runoff into rivers and aquaculture systems — critical for Malaysia’s food security.

🔎 Identifying the on-farm factors that degrade fish feed efficiency

💰 Did you know that 30 to 70% of intensive fish farm production costs come from feed?

📈 Improving feed efficiency is one of the fastest ways to boost profitability!

📖 The concept of “feed efficiency” can be defined as how an animal uses its feed, i.e. how much it eats and how much it grows. Several indicators exist to estimate feed efficiency in animals, but the most common one is feed conversion ratio (FCR) defined as FCR = feed intake/body weight gain.

🐟 For instance, if FCR = 1.7, it means that 1.7 kg of feed is necessary for fish to gain 1 kg of weight. As fish feed is particularly expensive, FCR should be as low as possible to increase farm profitability!

The factors underlying FCR value can be classified in three categories:

🍜 Nutrition: formulating the best feed for the fish

🧬 Genetics: using selective breeding to produce fish strains more efficient than normal

🧑‍🌾 Husbandry: applying the right on-farm procedures to preserve fish feed efficiency

🔬 Feed manufacturers focus on improving the nutritional aspects, while hatcheries and research centres develop selective breeding programs.

❗ Fish farmers’ direct control is mostly on husbandry.

👋 Here are some common mistakes to be careful about:

🍔 Don’t overfeed your fish: their growth rate will quickly reach a plateau if the feeding rate is increased. This higher feed intake with no significant growth improvement results in a degraded FCR. Even worse, if the feeding rate is really too high, fish will waste their precious feed, degrading even more farm profitability!

🌡️ Monitor closely the environmental parameters, notably water temperature and oxygenation. For instance, in Nile tilapia, FCR is at its lowest when water temperature is around 28°C, while increasing dissolved oxygen concentration lowers fish FCR (review by Mengistu et al., 2020).

😰 Avoid stocking fish at a too high density as it will degrade their FCR too. More generally, make sure that environmental conditions are not stressful for fish (e.g. poor water quality, presence of external disturbance). Indeed, cortisol (stress hormone) secretion correlates with degraded FCR.

⏱️ Don’t wait too much before harvesting your production. Bigger fish exhibit higher FCR, so setting a too large size target before commercialising your production can markedly increase your feed cost.

🤔 What is the main challenge you face when trying to improve FCR on your farm? Let’s discuss solutions!

🌱 Why Oxygen Matters in Hydroponics

In soil, plant roots sip oxygen from tiny air-filled pores. In hydroponics, those roots are submerged or constantly wetted — meaning oxygen has to be actively supplied.

Without it: ❌ Roots suffocate → reduced nutrient uptake ❌ Hypoxia → root rot & pathogens ❌ Worst case → crop failure

🔑 How Oxygen Drives Plant Health

1. Root Respiration

Roots need O₂ for aerobic respiration → ATP → fuels active nutrient transport (N, P, K, Ca, Mg).

2. Nutrient Uptake Efficiency

Higher dissolved oxygen (DO) = stronger proton pumps = faster ion uptake.

👉 Lettuce & basil in NFT: 30–50% faster growth at DO ~7–8 mg/L vs <3 mg/L.

3. Disease Suppression

Hypoxic conditions = Pythium thrives. Aerobic conditions = beneficial microbes dominate.

4. Temperature Interaction

Warm water = less O₂

• At 20 °C: ~9 mg/L saturation

• At 28 °C (SE Asia norm): ~7 mg/L ➡ Vertical farms must over-aerate or chill water.

🛠 Practical Tips for Vertical Farms

• Aeration methods: oxygen diffusers, liquid O₂ dosing

• Target DO levels: ≥6 mg/L = acceptable 7–8 mg/L = optimal <3 mg/L = hypoxic stress zone

• Design improvements: Use recirculating chillers + inline aeration (but CAPEX heavy).

📈 Commercial Take

• ROI: Better DO → faster growth cycles → more harvests per year.

• Risk: Overlooked O₂ = silent crop killer.

• Innovation: Nanobubble oxygenation stabilizes O₂ & controls biofilms (but adds CAPEX).

👉 Oxygen isn’t just a “supporting actor” in hydroponics. It’s the hidden yield driver — the difference between lush romaine and limp roots.

💬 Got questions? Drop us a message!

🌊 How Oxygen Levels Shape Microbial Communities in Aquaculture

Yes, we are still talking about oxygen in this second bulletin!

In aquaculture, dissolved oxygen (DO) isn’t just another water quality metric, it’s the lifeline of your system.
Hypoxia usually means <3 mg/L, but many sensitive species will already be stressed above that threshold.

What Happens Under Low DO?

• Microbial shift: Beneficial aerobic bacteria (your waste-processing “clean-up crew”) slow down. Anaerobes step in, leaving behind toxic byproducts — ammonia, nitrite, hydrogen sulfide, methane.

• Nitrification stalls: Nitrosomonas and Nitrobacter can’t function well, so ammonia and nitrite accumulate, stressing or even killing stock.

• Pathogens rise: Vibrio and Aeromonas (facultative anaerobes) thrive in low oxygen, while fish and shrimp immunity collapses.

• Algal boom-and-bust: Algal die-offs dump organic matter, driving DO even lower — a vicious cycle that favors disease.
  
  

Think of it like a crowded nightclub where the bouncers (aerobic microbes) step outside for a smoke break… and suddenly the troublemakers (pathogens) slip in and take over the dance floor.

🔑 Key Takeaways for Farmers

• Keep DO safely above 5 mg/L.

• Invest in proper aeration and circulation.

• Avoid overfeeding and manage organic load.

• Probiotics (aerobic strains) help — but only if there’s enough oxygen for them to work!

• Monitor DO at night and early morning when photosynthesis shuts down and respiration dominates.

💡 Bottom line: In aquaculture, oxygen is your best insurance policy. Lose it, and you don’t just lose water quality — you hand pathogens the upper hand.

🫧 Water oxygenation in fish farming: a topic too often overlooked

⁉️ The title of this post can seem paradoxical: why would fish farmers neglect a parameter that can lead in a few hours to the loss of one, or even several years of hard work?

🐟 Because in some fish farms such a disaster actually never happens: the water renewal rate is high enough compared to the density of fish to prevent any massive mortality event. Recently, we visited a fish farm where water oxygenation was not monitored, and no device was used to increase water oxygen concentration, except a few paddle wheels.

‼️ We were surprised to see that some fish were more than a decade old, proving that such a set-up can work without any accident happening for many years, although the climate is tropical. However, this is only the tip of the iceberg…

🔎 After discussing with the farmers, they told us that the fish growth was underwhelming, and that they were facing chronic health issues (notably skin lesions). We also observed that the fish were rather lethargic, with a low appetite: they were wasting the feed that was supplied to them.

📉 This is the hidden part of the hypoxia iceberg! The lack of oxygen is often not a sudden killer, but a chronic one that silently saps performance! The water oxygen concentration is high enough for animals to survive, but already too low for them to fulfill all their necessary biological functions…

The sublethal effects of hypoxia notably include:

1️⃣ Reduced swimming activity

2️⃣ Degraded growth and feed efficiency, high feed wastage

3️⃣ Lower fertility

4️⃣ Impaired embryonic development and high mortality in juveniles

5️⃣ Weaker immune system leading to a surge of disease outbreaks

6️⃣ Higher secretion of cortisol (stress hormone)

👍 Fortunately, many tech tools now exist to end hypoxia: IoT-based systems that track oxygenation with high precision, AI programs that detect suspicious patterns, and nanobubble generators that ensure efficient and long-lasting oxygenation.

If these issues sound familiar to you, do not hesitate to contact us!