REGISTRATION RIGHTS AGREEMENT

Exhibit 4.1

Execution Version

REGISTRATION RIGHTS AGREEMENT

among

SMITHFIELD FOODS, INC.,

and

CONTIGROUP COMPANIES, INC.

Dated: May 7, 2007

TABLE OF CONTENTS

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REGISTRATION RIGHTS AGREEMENT

REGISTRATION RIGHTS AGREEMENT, dated May 7, 2007 (this “ Agreement ”), among Smithfield Foods, Inc., a Virginia corporation (the “ Company ”) and ContiGroup Companies, Inc., a Delaware corporation (“ Stockholder ”). Capitalized terms used but not otherwise defined herein shall have the respective meanings ascribed to such terms in Section 1.

R E C I T A L S :

A. Pursuant to the Agreement and Plan of Merger, dated as of September 17, 2006 (the “ Merger Agreement ”), among the Company, KC2 Merger Sub, Inc. and Premium Standard Foods, Inc. (“ PSF ”), each outstanding share of the common stock, par value $0.01 per share, of PSF will be converted into the right to receive 0.6780 shares of Common Stock and $1.25 in cash, subject to adjustment as provided in the Merger Agreement.

B. Concurrently with the Merger Agreement, the Company, Stockholder and PSF entered into the Voting Agreement, dated September 17, 2006 pursuant to which the Company, among other things, has agreed to grant “piggy-back” registration rights to Stockholder with respect to the Registrable Securities as set forth in this Agreement.

NOW, THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, the parties hereto agree as follows:

1. Definitions and Interpretation .

(a) Certain Definitions . As used in this Agreement, and unless the context requires a different meaning, the following terms have the meanings indicated:

“ Affiliate ” means any Person who is an “affiliate” as defined in Rule 12b-2 promulgated under the Exchange Act.

“ Agreement ” means this Agreement, as the same may be amended, supplemented or modified in accordance with the terms hereof.

“ Board of Directors ” means the board of directors of the Company.

“ Business Day ” means any day other than a Saturday, Sunday or other day on which commercial banks in the State of New York are authorized or required by law or executive order to close.

“ Closing Price ” means, with respect to the Registrable Securities, as of the date of determination: (i) if the Registrable Securities are listed on a national securities exchange, the closing price per share of a Registrable Security on such date or, if no such

closing price on such date is reported, the average of the closing bid and asked prices on such date, as officially reported on the principal national securities exchange on which the Registrable Securities are then listed or admitted to trading; or (ii) if the Registrable Securities are not then listed or admitted to trading on any national securities exchange, the last sale price or, if such last sale price is not reported, the average of the high bid and low asked prices in the over-the-counter market, as reported by The Nasdaq Stock Market LLC or such other system then in use; or (iii) if on any such date the Registrable Securities are not quoted by any such organization, the average of the closing bid and asked prices as furnished by a professional market maker making a market in the Registrable Securities selected by the Company; or (iv) if none of (i), (ii) or (iii) is applicable, a market price per share determined in good faith by the Board of Directors. If trading is conducted on a continuous basis on any exchange, then the closing price shall be as at 4:00 P.M. New York City time.

“ Commission ” means the Securities and Exchange Commission.

“ Common Stock ” means the common stock, par value $0.50 per share, of the Company or any other capital stock of the Company into which such stock is reclassified or reconstituted and any other common stock of the Company.

“ Company ” has the meaning set forth in the preamble to this Agreement.

“ Company Underwriter ” has the meaning set forth in Section 3(a).

“ Designated Holder ” means Stockholder, and any transferee (whether direct or indirect) of Stockholder to whom Registrable Securities have been transferred in accordance with Section 8(f), other than a transferee to whom Registrable Securities have been transferred pursuant to a Registration Statement under the Securities Act or Rule 144 or Regulation S promulgated under the Securities Act.

“ Designated Holder Free Writing Prospectus ” means each Free Writing Prospectus prepared by or on behalf of the relevant Designated Holder or used or referred to by such Designated Holder in connection with the offering of Registrable Securities.

“ Disclosure Package ” means, with respect to any offering of securities, (i) the preliminary Prospectus, (ii) each Free Writing Prospectus and (iii) all other information, in each case, that is deemed, under Rule 159 promulgated under the Securities Act, to have been conveyed to purchasers of securities at the time of sale of such securities (including a contract of sale).

“ Exchange Act ” means the Securities Exchange Act of 1934 and the rules and regulations of the Commission promulgated thereunder.

“ Free Writing Prospectus ” means any “free writing prospectus” as defined in Rule 405 promulgated under the Securities Act.

“ Holders’ Counsel ” has the meaning set forth in Section 5(a)(i).

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“ Incidental Registration ” has the meaning set forth in Section 3(a).

“ Indemnified Party ” has the meaning set forth in Section 6(c).

“ Indemnifying Party ” has the meaning set forth in Section 6(c).

“ Inspectors ” has the meaning set forth in Section 5(a)(viii).

“ Liability ” has the meaning set forth in Section 6(a).

“ Lock-up Agreements ” has the meaning set forth in Section 4(a).

“ Market Price ” means, on any date of determination, the average of the daily Closing Price of the Registrable Securities for the immediately preceding 30 days on which the national securities exchanges are open for trading.

“ Merger Agreement ” has the meaning set forth in Recital A.

“ NASD ” means the National Association of Securities Dealers, Inc.

“ Person ” means any individual, firm, corporation, partnership, limited liability company, trust, incorporated or unincorporated association, joint venture, joint stock company, government (or an agency or political subdivision thereof) or other entity of any kind, and shall include any successor (by merger or otherwise) of such entity.

“ Prospectus ” means any “prospectus” as defined in Rule 405 promulgated under the Securities Act.

“ Records ” has the meaning set forth in Section 5(a)(viii).

“ Registrable Class Securities ” means the Registrable Securities and any other securities of the Company that are of the same class as the relevant Registrable Securities.

“ Registrable Securities ” means each of the following: (a) any and all shares of Common Stock received in the Merger and owned by the Designated Holders or any other capital stock of Parent into which such stock is reclassified or reconstituted; and (b) any shares of Common Stock issued or issuable to any of the Designated Holders with respect to the Registrable Securities by way of stock dividend or stock split or in connection with a combination of shares, recapitalization, merger, consolidation or other reorganization or otherwise and any shares of Common Stock or voting common stock issuable upon conversion, exercise or exchange thereof.

“ Registration Expenses ” has the meaning set forth in Section 5(d).

“ Registration Statement ” means a registration statement filed pursuant to the Securities Act.

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“ Securities Act ” means the Securities Act of 1933 and the rules and regulations of the Commission promulgated thereunder.

“ Transfer ” means, with respect to any security, the offer for sale, sale, pledge, transfer or other disposition or encumbrance (or any transaction or device that is designed to or could be expected to result in the transfer or the disposition by any Person at any time in the future) of such security, and shall include the entering into of any swap, hedge or other derivatives transaction or other transaction that transfers to another in whole or in part any rights, economic benefits or risks of ownership, including by way of settlement by delivery of such security or other securities in cash or otherwise.

“ underwritten public offering ” of securities means a public offering of such securities registered under the Securities Act in which an underwriter, placement agent or other intermediary participates in the distribution of such securities.

(b) Interpretation . Unless otherwise noted:

(i) All references to laws, rules, regulations and forms in this Agreement shall be deemed to be references to such laws, rules, regulations and forms, as amended from time to time or, to the extent replaced, the comparable successor thereto in effect at the time.

(ii) All references to agencies, self-regulatory organizations or governmental entities in this Agreement shall be deemed to be references to the comparable successor thereto.

(iii) All references to agreements and other contractual instruments shall be deemed to be references to such agreements or other instruments as they may be amended from time to time.

(iv) Whenever the words “include,” “includes” or “including” are used in this Agreement, they shall be deemed to be followed by the words “without limitation.”

2. General; Securities Subject to this Agreement .

(a) Grant of Rights . The Company hereby grants “piggy-back” registration rights to the Designated Holders upon the terms and conditions set forth in this Agreement.

(b) Registrable Securities . For the purposes of this Agreement, Registrable Securities will cease to be Registrable Securities when (i) a Registration Statement covering such Registrable Securities has been declared effective under the Securities Act by the Commission and such Registrable Securities have been disposed of pursuant to such effective Registration Statement, (ii) the entire amount of the Registrable Securities owned by the relevant Designated Holder may be sold in a single fiscal quarter pursuant to Rule 144 promulgated under the Securities Act (iii) the Registrable Securities transferred to a Person not entitled to the registration rights granted by this Agreement, or (iv) such Registrable Securities cease to be outstanding.

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(c) Holders of Registrable Securities . A Person is deemed, and shall only be deemed, to be a holder of Registrable Securities if such Person owns Registrable Securities or has a right to acquire such Registrable Securities and such Person is a Designated Holder. If the Company receives conflicting instructions, notices or elections from two or more Persons with respect to the same Registrable Securities, the Company may act upon the basis of the instructions, notice or election received from the registered owner of such Registrable Securities. Registrable Securities issuable upon exercise of an option or upon conversion, exercise or exchange of another security shall be deemed outstanding for the purposes of this Agreement.

3. Incidental or “Piggy-Back” Registration .

(a) Request for Incidental or “Piggy-Back” Registration . At any time after the date hereof, if the Company proposes to file a Registration Statement with respect to an offering by the Company for its own account (other than a Registration Statement on Form S-4 or S-8) or for the account of any stockholder of the Company, then the Company shall give written notice of such proposed filing to each of the Designated Holders at least 20 days before the anticipated filing date, and such notice shall describe the proposed registration, offering price (or reasonable range thereof) and distribution arrangements, and offer such Designated Holders the opportunity to register the number of Registrable Securities as each such Designated Holder may request (an “ Incidental Registration ”). In connection with any Incidental Registration under this Section 3(a) involving an underwritten public offering, the Company shall use its reasonable efforts (within 20 days after the notice provided for in the preceding sentence) to cause the managing underwriter or underwriters (the “ Company Underwriter ”) to permit each of the Designated Holders who has requested in writing to participate in the Incidental Registration to include the number of such Designated Holder’s Registrable Securities specified by such Designated Holder in such offering on the same terms and conditions as the securities of the Company or for the account of such other stockholder, as the case may be, included therein. In connection with any Incidental Registration under this Section 3(a) involving an underwritten public offering, the Company shall not be required to include any Registrable Securities in such underwritten public offering unless the Designated Holders thereof accept the terms of the underwritten public offering as agreed upon between the Company, such other stockholders, if any, and the Company Underwriter, and then only in such quantity as the Company Underwriter believes will not jeopardize the success of the offering by the Company. If the Company Underwriter determines that the registration of all or part of the Registrable Securities which the Designated Holders have requested to be included would materially adversely affect the success of such offering, then the Company shall include in such Incidental Registration only the aggregate amount of Registrable Securities that the Company Underwriter believes may be sold without any such material adverse effect and shall include in such registration, first , all of the securities to be offered for the account of the Company; and second , the Registrable Securities to be offered for the account of the

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Designated Holders pursuant to this Section 3 and the securities for the account of any other stockholders of the Company, pro rata based on the number of Registrable Securities owned by each such Designated Holder or securities for the account of such other stockholder.

(b) Expenses . The Company shall bear all Registration Expenses in connection with any Incidental Registration pursuant to this Section 3, whether or not such Incidental Registration becomes effective.

4. Lock-up Agreements .

(a) Designated Holder Lock-up Agreements . To the extent (i) requested by the Company Underwriter, in the case of an underwritten public offering, and (ii) the Company and all of the Company’s officers, directors and holders in excess of 1% of its outstanding shares of capital stock execute agreements identical to or more restrictive than those referred to in this Section 4(a), each Designated Holder agrees (x) not to effect any Transfer of any Registrable Class Securities or any securities convertible into or exchangeable or exercisable for such Registrable Class Securities and (y) not to make any request for the registration of the Transfer of any Registrable Class Securities or any securities convertible into or exchangeable or exercisable for such Registrable Class Securities, in each case, during the period beginning on the effective date of the Registration Statement for such public offering and ending on the date that is 90 days after the date of the final Prospectus relating to such public offering (or such shorter period, if any, mutually agreed upon by such Designated Holder and the requesting party), except as part of such public offering. Upon request by the Company Underwriter, each Designated Holder shall enter into customary lock-up agreements (“ Lock-up Agreements ”) on terms consistent with the preceding sentence and no less favorable to the Designated Holders than those applicable to any other stockholder of the Company that signs a Lock-up Agreement in connection with such offering. No Designated Holder subject to this Section 4(a) shall be released from any obligation under any agreement, arrangement or understanding entered into pursuant to this Section 4(a) unless all other Designated Holders subject to the same obligation are also released.

(b) Third Party Beneficiaries in Lock-up Agreements . Any Lock-up Agreements executed by the Designated Holders pursuant to this Section 6 shall contain provisions naming the Company as an intended third-party beneficiary thereof and requiring the prior written consent of the Company for any amendments thereto or waivers thereof.

5. Registration Procedures .

(a) Obligations of the Company . Whenever registration of Registrable Securities has been requested or required pursuant to Section 3, the Company shall use its reasonable best efforts to effect the registration and sale of such Registrable Securities in accordance with the intended method of distribution thereof as promptly as practicable, and in connection with any such request or requirement, the Company shall:

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(i) as expeditiously as possible, prepare and file with the Commission a Registration Statement on any form for which the Company then qualifies or which counsel for the Company shall deem appropriate and which form shall be available for the sale of such Registrable Securities in accordance with the intended method of distribution thereof, and cause such Registration Statement to become effective; provided , however , that (A) before filing a Registration Statement or Prospectus or any amendments or supplements thereto (including any documents incorporated by reference therein), or before using any Free Writing Prospectus, the Company shall provide counsel selected by the Designated Holders holding a majority of the Registrable Securities of Designated Holders being registered in such registration (“ Holders’ Counsel ”) and any other Inspector with an adequate and appropriate opportunity to review and comment on such Registration Statement, each Prospectus included therein (and each amendment or supplement thereto) and each Free Writing Prospectus to be filed with the Commission, subject to such documents being under the Company’s control, and (B) the Company shall notify the Holders’ Counsel and each seller of Registrable Securities pursuant to such Registration Statement of any stop order issued or threatened by the Commission and take all actions required to prevent the entry of such stop order or to remove it if entered;

(ii) as expeditiously as possible, prepare and file with the Commission such amendments and supplements to such Registration Statement and the Prospectus used in connection therewith as may be necessary to keep such Registration Statement effective for the lesser of (A) 180 days and (B) such shorter period which will terminate when all Registrable Securities covered by such Registration Statement have been sold;

(iii) as expeditiously as possible, furnish to each seller of Registrable Securities, prior to filing a Registration Statement, at least one copy of such Registration Statement as is proposed to be filed, and thereafter such number of copies of such Registration Statement, each amendment and supplement thereto (in each case including all exhibits thereto), the Prospectus included in such Registration Statement (including each preliminary Prospectus), any Prospectus filed pursuant to Rule 424 promulgated under the Securities Act and any Free Writing Prospectus as each such seller may reasonably request in order to facilitate the disposition of the Registrable Securities owned by such seller;

(iv) as expeditiously as possible, register or qualify such Registrable Securities under such other securities or “blue sky” laws of such jurisdictions as any seller of Registrable Securities may request, and to continue such registration or qualification in effect in such jurisdiction for as long as permissible pursuant to the laws of such jurisdiction, or for as long as any such seller requests or until all of such Registrable Securities are sold, whichever is shortest, and do any and all other acts and things which may be reasonably necessary or advisable to enable any such seller to consummate the disposition in such jurisdictions of the Registrable Securities owned by such seller; provided , however , that the Company shall not be required to (A) qualify generally to do business in any jurisdiction where it would not otherwise be required to qualify but for this Section 5(a)(iv), (B) subject itself to taxation in any such jurisdiction or (C) consent to general service of process in any such jurisdiction;

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(v) as expeditiously as possible, notify each seller of Registrable Securities: (A) when a Disclosure Package, Prospectus, any Prospectus supplement, a Registration Statement or a post-effective amendment to a Registration Statement has been filed with the Commission, and, with respect to a Registration Statement or any post-effective amendment, when the same has become effective; (B) of any request by the Commission or any other federal or state governmental authority for amendments or supplements to a Disclosure Package, Registration Statement or related Prospectus or for additional information; (C) of the issuance by the Commission or any other federal or state governmental authority of any stop order suspen