With a signed gift letter, proof of the relationship, and the parents' own records: quota transfer documents, livestock sale invoices, bank deposits and tax returns. The donor's source is examined as closely as the investor's.
The parents' trail is part of the investor's file
USCIS accepts gifted funds as capital when the gift is genuine and the donor obtained the money lawfully, and it expects the donor's evidence to be as complete as the investor's. For a dairy-farming parent, that means the quota exchange or transfer records showing the sale price and buyer, sale invoices for the cattle, the deposits of those proceeds into the parents' account and the tax returns reporting them. Add a gift letter signed by both parents stating the amount, the date, that the gift is unconditional and that no repayment is expected, plus any required gift-tax or reporting filings.
Show the transfer from the parents' account to the investor's and onward to the enterprise. Birth certificates establish the relationship. A gift that arrives in cash, or from an account the parents cannot explain, breaks the chain.
Certified translations are required for French documents; the farmland sale is documented separately with its deed, agreement and closing statement.