Feed for fry

🔹 Fry – very small, not yet hatched fish, often from feed eggs

🔹 Juvenile – young fish a few weeks/old, size from a few millimeters to cm

🔹 Their digestive system is sensitive and not yet mature

➡️ Feed for fry and fry ARE NOT the same as for adult fish — they would be poorly digested by adult fish and cause health problems.

🧠 How fry and fry feeds work
1️⃣ High content of easily digestible proteins

Proteins are the building blocks for muscle and growth

Fry and fry grow quickly → they need a higher content of animal proteins

2️⃣ Small particles (feed particles/micron pellets)

Fry cannot chew large granules

The feed must be microscopically small or disintegrable in water

3️⃣ High energy density

They need quick energy for growth, movement and organ development

4️⃣ Digestion and immunity support

Nutritional supplements (enzymes, probiotics, vitamins) are common in fry feeds

🏠 Fry feed requirements
🌡️ Water temperature

Temperature affects metabolism:

Higher temperature → faster growth and digestion

Lower temperature (<15°C) → slower digestion → intensity must be limited feeding

🧬 Digestive system

Not yet fully developed

Need microscopic, easily digestible ingredients

Low proportion of heavy carbohydrates

⚖️ Nutrient ratios

Protein: 45–60% (high amount)

Fats / lipids: 8–15% (energy source)

Carbohydrates: low content

Vitamins and minerals: enriched for the development of bone and internal structures

🐣 Nature of food for fry and fry

✔️ prefers microscopic or small particles
✔️ food should dissolve quickly
✔️ fish actively "hunt" for food at the bottom or in the water column

➡️ Food should be:

soluble or very small

no sharp edges

rich in animal protein

🩺 The impact of the right food on health

✅ Positive effects

✔️ fast, but healthy growth
✔️ strong immunity
✔️ stable vitality
✔️ prevention of bone deformities and diseases
✔️ better resistance to diseases

⚠️ Negative (with bad feed or overfeeding)

❌ slow growth
❌ accumulation of waste in the water
❌ reduced immune response
❌ digestive problems
❌ deformities

🧪 Common health problems in fry with improper feeding
🟠 1) Putrefactive fungi and skin diseases

Cause: aquatic environment with leftover food

Solution: small portions more often, clean water

🟡 2) Growth disorders and deformities

Cause: lack of protein or minerals

Solution: special feeds with the right combination of nutrients

🔵 3) Constipation / digestive problems

Cause: high proportion of insoluble carbohydrates

Solution: high-quality feeds with enzymatic support

🍱 Types of feeds for fry and fry
🔹 1) Micropellets / microgranules

Size: often <0.5mm to 1mm

Most common form for young fish

Advantages
✔️ high digestibility
✔️ distribution in the water column
✔️ regular nutrient composition

Disadvantages
❌ sensitive to water quality (poor water flow will quickly break them down)

🔹 2) Water-soluble flakes / suspension feeds

Dissolve gradually → food available for longer

Suitable for low food activity

Advantages
✔️ easy to digest
✔️ reduces the risk of digestive problems

Disadvantages
❌ requires controlled dosage

🔹 3) Live or frozen foods (supplement)

Artemia, daphnia, nits

Support a natural diet

Advantages
✔️ very attractive to fish
✔️ support natural behavior

Disadvantages
❌ difficult to store
❌ must be prepared safely (pathogen-free)

🔹 4) Special "starter" feeds

Designed for the first days after hatching

Optimized for absorption

Advantages
✔️ ideal for the first stage
✔️ reduces mortality

Disadvantages
❌ not suitable for older juvenile stages

⚖️ Advantages and disadvantages of different feeds
Type of feed Advantages Disadvantages
Micropellets / microgranules balanced, quickly recognizable sensitive to water quality
Water-soluble flakes very easy to digest precise dosage required
Live / frozen supplementary stimulate natural behavior storage, risk of microorganisms
Starter feeds ideal for the first days short-term use
🧠 How to choose the right feed for fry and fry
1️⃣ By fish size

Fry very small → microgranules or suspension products

Fry (larger juvenile) → micropellets

2️⃣ By age stage

<1 week: "starter" / soluble

1–4 weeks: microgranules combined with supplements

>4–8 weeks: micropellets gradually as a base

3️⃣ According to water quality

☑️ clean and stable parameters → any quality food
☑️ water fluctuations → weigh food with high digestibility

4️⃣ According to season

Warm season → more active feeding

Cold season → reduce feeding intensity

🍽️ How and when to feed fry and fry
📆 Seasonal preference

Spring - summer: more often, smaller portions

Autumn - winter: significantly reduce depending on water temperature

🍽️ Feeding principles

✔️ feed only as much as they eat in 30–45s
✔️ often, but small portions
✔️ avoid excess residues in the water
✔️ regular water quality control

🧠 The impact of food on water quality

Bad foods or overfeeding → increased:
🟥 ammonia
🟧 nitrites
🟨 algae turbidity
🟩 odor