I. Early Spring Feeding (Water Temperature 10–18°C)

1. Physiological Context
   After winter fasting, the koi’s digestive system is in a "semi-dormant" state, with low intestinal flora activity. Sudden introduction of high-protein feed can easily lead to indigestion.
2. Key Benefits
   • Dietary fiber stimulates intestinal peristalsis, gently reactivating digestive function.
   • Supplementation of vitamins C and K helps repair mucosal tissues that may have been weakened during winter.
   • Low-energy appetite stimulation reduces the risk of enteritis from spring "overeating syndrome."
3. Practical Guidelines
   • Alternate with main feed (e.g., one meal of cabbage, one meal of wheat germ feed).
   • Continue for 2–3 weeks, gradually reducing as water temperatures rise above 18°C.
     

II. Late Autumn Feeding (Water Temperature 18–10°C)

1. Physiological Context
   As water temperatures drop, koi metabolism gradually slows. It is important to clear accumulated intestinal contents beforehand to create a "clean gut" for the winter fasting period.
2. Key Benefits
   • Cellulose adsorbs excess fat in the intestines, helping prevent fatty liver during overwintering.
   • Vitamin reserves boost winter immunity.
   • Moisture regulation alleviates constipation caused by dry autumn feeds.
3. Practical Guidelines
   • When water temperature falls below 15°C, stop protein-based feeds and switch to a "cabbage + wheat germ feed" combination.
   • Cease all feeding one week before water temperature drops to 10°C.

III. Refined Preparation Process for Cabbage

1. Selection Criteria
   • Choose older leaves from frost-exposed cabbage (higher cellulose content, lower pesticide residue).
   • Avoid refrigerated cabbage (damaged cell structure leads to nutrient loss).
2. Preprocessing Steps
   • Remove the outer 3–4 leaves that may be contaminated.
   • Soak in 0.3% saltwater for 15 minutes (to remove potential parasites).
   • Blanch in boiling water for 5 seconds, then immediately chill in ice water to retain crispness and nutrients.
3. Feeding Form
   • Cut into strips (5 cm long × 0.3 cm wide) for easy pecking.
   • Secure to the pond wall with a stainless-steel clip to simulate natural foraging.
     

IV. Synergistic Feeding Combinations

1. Early Spring "Awakening Mix"
   70% cabbage strips + 20% blanched pumpkin puree + 10% spirulina powder, fed twice weekly.
2. Late Autumn "Intestinal Cleansing Mix"
   60% cabbage strips + 30% unsalted seaweed flakes + 10% lactobacillus preparation, fed once weekly.

V. Contraindications and Risk Warnings

1. When Not to Feed Cabbage
   • Water temperature <10°C or >25°C.
   • Koi show signs of digestive issues (e.g., floating feces, reddened vent).
   • During rainy periods or when daily pH fluctuations exceed 0.5.
2. Risks of Overfeeding
   • Excessive cellulose may adsorb minerals, potentially leading to trace element deficiencies.
   • Coarse fibers from cabbage stems could scratch the intestinal lining (must be thoroughly removed).