When sourcing Vitamin A 1000 (Retinyl Acetate or Retinyl Palmitate), the primary specification is the potency, which must be at least 1,000,000 IU/g. You must verify the stability of the beadlet or powder, as Vitamin A is highly sensitive to oxidation, heat, and light. Ensure the product features micro-encapsulation technology to protect the active ingredient during the feed premixing and pelleting processes. Additionally, check for particle size uniformity to ensure even distribution within the feed mash.