Feed Formulation, Feed Technology & Feeding M

• Fungal Contamination and Mycotoxins:
• During storage in warm and humid tropical climates, finished aquafeeds and feed raw materials are vulnerable to mold growth (e.g., Aspergillus flavus, Penicillium, Fusarium), which produce lethal mycotoxins (aflatoxin $B_1$, ochratoxin, zearalenone).
• Propionic Acid and Propionates:
• Propionic acid (and its calcium/sodium salts) is the most widely utilized and effective antifungal agent (mold inhibitor) in compound feed manufacturing.
• It readily penetrates mold cell walls in un-ionized form, disassociates intracellularly to lower pH, disrupts cellular proton gradients, and inhibits metabolic enzymes.
• nalysis:
• (Propionic Acid): Correct.
• Options 1, 2, 4: Inorganic salts and strong mineral acids not used as safe organic mold inhibitors.

Correct option: (3) Propionic Acid

• Water Stability of Crustacean Feeds:
• Shrimps (Penaeus vannamei, Penaeus monodon) are slow, continuous bottom feeders that manipulate and nibble feed pellets slowly using their maxillipeds and mandibles.
• To prevent rapid physical disintegration and nutrient leaching into the water, commercially formulated shrimp feeds must exhibit a minimum water stability of 2 hours (retaining $\ge 85\%$ of their physical dry mass intact).
• Correct Option: Option 3 (2 hours).

• Feed Attractants in Aquaculture:
• Aquatic animals locate and ingest feed through chemoreception (olfaction and gustation).
• Feed attractants are low-molecular-weight substances incorporated into artificial feeds to enhance palatability and stimulate voluntary feed consumption, especially when replacing fishmeal with less palatable plant ingredients.
• Prominent chemoattractants include betaine (trimethylglycine), free amino acids (alanine, glycine, taurine, glutamic acid), nucleotides (inosine-5'-monophosphate, IMP), and krill meal.
• nalysis:
• (Attractants): Correct. Directly stimulates feed search and ingestion.
• (Antioxidants): Preserve feed freshness by inhibiting lipid oxidation.
• (Hormones): Regulate physiology/growth, not feeding stimulants.
• (Pigments): Impart coloration to flesh or exoskeleton.

Correct option: (3) Attractants