Each packer, market agency, or dealer purchasing livestock shall, before the close of the next business day following the purchase of livestock and transfer of possession thereof, deliver to the seller or his duly authorized representative the full amount of the purchase price: Provided, That each packer, market agency, or dealer purchasing livestock for slaughter shall, before the close of the next business day following purchase of livestock and transfer of possession thereof, actually deliver at the point of transfer of possession to the seller or his duly authorized representative a check or shall transfer funds for the full amount of the purchase price to the account of the seller by wire, electronic funds transfer, or any other expeditious method determined appropriate by the Secretary for the full amount of the purchase price; or, in the case of a purchase on a carcass or “grade and yield” basis, the purchaser shall make payment by check at the point of transfer of possession or shall transfer funds for the full amount of the purchase price to the account of the seller by wire, electronic funds transfer, or any other expeditious method determined appropriate by the Secretary for the full amount of the purchase price not later than the close of the first business day following determination of the purchase price: Provided further, That if the seller or his duly authorized representative is not present to receive payment at the point of transfer of possession, as herein provided, the packer, market agency or dealer shall transfer funds for the full amount of the purchase price by wire, electronic funds transfer, or any other expeditious method determined appropriate by the Secretary or place a check in the United States mail for the full amount of the purchase price, properly addressed to the seller, within the time limits specified in this subsection, such action being deemed compliance with the requirement for prompt payment.