Cal. Civil Code § 3080.21

At any time after a lien has arisen, the lienholder may propose to retain any portion or all of the livestock in satisfaction of any portion or all of the claim against the owner or other person indebted to the lienholder for livestock services. The proposal shall be made in writing to the owner and written notice thereof shall be given to any person entitled to receive notice under subdivision (a) of Section 3080.17. If, within 21 days after the notice was sent, the lienholder receives objection in writing from a person entitled to receive notification, the lienholder must proceed to sell the livestock and account for the proceeds pursuant to this chapter. In the absence of such written objection, the lienholder may retain the livestock, or so much thereof as proposed, in satisfaction of all or a portion of the claim against the owner and other person indebted to the lienholder for livestock services, upon the owner’s and such other person’s execution of a release conforming to Section 3080.20.