I. Scientific Management of Feed Storage

1. Subpackaging, Light Protection, and Moisture Prevention
   • Large packages of feed should be divided into portions for 7-10 days of use and stored in opaque, airtight bags or containers with air removed before sealing.
   • Storage environment: A cool, dry place with temperature ≤20°C and humidity ≤60% (refrigeration can extend shelf life by 30%).
2. Preventing Oxidation and Deterioration
   • Add food-grade deoxidizers (1-2 packets per kilogram of feed).
   • Avoid storing together with aquatic medicines or disinfectants to prevent cross-contamination.
3. Shelf Life Monitoring
   • Use within 45 days after opening in summer, and within 90 days in winter.
   • Regularly check for rancid odors, clumping, or insect infestation.
     

II. Pre-Feeding Preparation

1. Temperature Adjustment (After Refrigeration)
   • Allow refrigerated feed to rest for 1-2 hours until the temperature difference with the environment is <3°C.
   • Avoid directly feeding cold feed to prevent digestive stress in koi.
2. Activation of Active Ingredients
   • Probiotic feed: Activate by soaking in 30°C warm water (feed-to-water ratio 1:0.3) for 5 minutes.
   • Vitamin-fortified feed: Avoid prolonged soaking (water-soluble vitamins can lose >40% in 10 minutes).
3. Safety Testing
   • Soak a 10g sample from each batch before feeding and observe:
     Normal: No significant pigment leaching and clear water within 30 minutes.
     Abnormal: Rapid color loss or cloudy water (may indicate artificial coloring or mold).

III. Precise Control During Feeding

1. Time and Space Distribution Principles
   • Single feeding duration ≤5 minutes (remove uneaten food immediately after this time).
   • Feeding points should be away from filter inlets, with 2-3 dispersed feeding areas.
2. Seasonal Adjustments

   Season	Feeding Ratio	Notes
   Spring (15-20°C)	60% of daily ration	Add 0.5% digestive enzymes
   Summer (>25°C)	100% of daily ration	Main feeding between 05:00-08:00
   Autumn (18-22°C)	80% of daily ration	Add 1% spirulina powder
   Winter (<10°C)	Fasting or 5% of daily ration	Use wheat germ-based feed

3. Adjustments for Special Conditions
   • Breeding period: Increase protein content to 42% + add astaxanthin.
   • Post-operative recovery: Use fermented feed (probiotics ≥10⁸ CFU/g).
   • Color enhancement period: Color-enhancing feed should not exceed 30% of total ration.

IV. Coordinated Management of Feed and Water Quality

1. Uneaten Feed Monitoring System
   • Install bottom-viewing mirrors to check for uneaten feed 30 minutes after feeding.
   • Adjust feed particle size or feeding frequency if uneaten feed exceeds 5% of the amount fed.
2. Water Quality Response Mechanism
   • Test ammonia levels 2 hours after feeding (safe threshold <0.1 mg/L).
   • Use slow-sinking feed to reduce surface oil film formation.

V. Feed Transition and Changeover

1. Brand/Formula Change
   • Implement a 7-day transition: gradually replace old feed with new at ratios of 1:3 → 1:1 → 3:1.
   • Add 0.2% fructooligosaccharides during transition to prevent intestinal stress.
2. Form Change
   • When switching between pellet and extruded feed, accompany with soaking and softening.
   • Transition from sinking to floating feed should be extended to 10 days.

VI. Correcting Common Misconceptions

1. Myth: "Higher Protein = Faster Growth"
   • Protein content exceeding koi requirements (45% for juveniles, 38% for adults) decreases conversion efficiency and burdens the liver and kidneys.
2. Risk of "Mixing Multiple Feeds for Better Nutrition"
   • Preservatives in different feed brands may counteract each other; it is recommended to use one primary brand with functional feeds as supplements.
3. Misconception: "Stop Vitamin Feed in Cold Periods"
   • Vitamin E supplementation (0.5g/kg feed) is still necessary in winter to maintain cold resistance.

VII. Smart Assistance Solutions

1. IoT-Based Feed Storage System
   • Smart grain bin: Automatically monitors temperature and humidity, with alerts for deviations.
   • Quantitative dispensing: Integrates with automatic feeders for precise portion control.
2. Feed Efficacy Evaluation
   • Monthly measurement of koi body length/weight growth curve.
   • Calculate Feed Conversion Ratio (FCR):

     FCR=Weight GainTotal Feed Given

     Ideal values should be maintained between 1.2 and 1.5.