<PAGE>
                                                                  EXHIBIT 10.50


              ASSIGNMENT AND ASSUMPTION OF PARTNERSHIP INTEREST AND
                            TERMINATION OF CONTRACTS


     ASSIGNMENT AND ASSUMPTION OF PARTNERSHIP INTEREST AND TERMINATION OF
CONTRACTS, dated as of July 24, 1997, by and among PROTYDE ONCOLOGY
THERAPEUTICS, INC., a Delaware corporation (the "PSub"), BIGMAR THERAPEUTICS,
INC., a Delaware Corporation (the "BSub"), PROTYDE-BIGMAR THERAPEUTICS, a
Delaware general partnership (the "Partnership"), PROTYDE PHARMACEUTICALS, 
INC., a Delaware corporation, formerly known as Protyde Corporation, ("Protyde")
and BIGMAR, INC., a Delaware corporation ("Bigmar").

     WHEREAS, the PSub and the BSub are parties to a Partnership Agreement dated
October 27, 1995 (the "Partnership Agreement"); and

     WHEREAS, PSub now desires to assign to BSub, and BSub desires to take by
assignment and assume, all of PSub's rights and obligations under the
Partnership Agreement, as set forth herein;

     WHEREAS, the Partnership and each of Protyde and Bigmar wish to terminate
certain contractual arrangements;

     NOW, THEREFORE, for good and valuable consideration, the receipt of which
is hereby acknowledged, the parties hereto agree as follows:

     1.   ASSIGNMENT OF PARTNERSHIP INTEREST.

          1.1.   ASSIGNMENT.  PSub hereby assigns to the BSub, it successors and
assigns all rights, claims, terms options and interests of the PSub under the
Partnership Agreement and in or to the property therein described (the
"Partnership Interest").

          1.2.   ASSUMPTION.  The BSub hereby assumes all the obligations of the
PSub under the Partnership Agreement and agrees to keep and perform all of the
covenants and obligations of the PSub under the Partnership Agreement.

          1.3.   CONSENT.  The BSub hereby consents to such assignment for all
purposes, including Section 11 of the Partnership Agreement.

     2.   CONSIDERATION.

          2.1.   PAYMENT.  In consideration of the sale of the Partnership
Interest to BSub, BSub shall on the date hereof:


<PAGE>

                 (a) pay to Protyde the sum of $2,000,000, in cash, by check for
                 immediately available funds or by wire transfer; and

                 (b) issue to Protyde or its designees warrants to purchase an
                 aggregate of 500,000 shares of Bigmar's Common Stock, $0.01 par
                 value per share, having an exercise price of $5.00 per share
                 and a term of five years in substantially the form attached
                 hereto as EXHIBIT A (the "Warrants").

          2.2.   RESTRICTED SECURITIES.  The Warrants and the shares issuable on
exercise thereof (the "Warrant Shares") will be "restricted securities" which
have not been registered under the Securities Act of 1933, as amended (the
"Securities Act"), and must be held until they are either registered or an
exemption from registration becomes available for their resale.

          2.3.   CURRENT PUBLIC INFORMATION.  During all periods in which
Bigmar's Common Stock is registered under the Securities Exchange Act of 1934,
as amended and the rules and regulations thereunder (the "Exchange Act"), Bigmar
will file all reports required under the Exchange Act, and will take such
further action as may be reasonably required to enable any holder of "restricted
securities" (as defined in Rule 144 adopted by the Securities and Exchange
Commission under the Securities Act) to sell such securities pursuant to Rule
144, as amended from time to time, or any similar rule or regulation hereafter
adopted by the Securities and Exchange Commission.

     3.   REPRESENTATIONS AND WARRANTIES OF THE PARTIES.

     Each party hereto (other than the Partnership) hereby makes the following
representations as to itself only:

          3.1.   ORGANIZATION AND QUALIFICATION.  Such party is a corporation
duly organized, validly existing and in good standing under the laws of its
jurisdiction of incorporation and has full corporate power and lawful authority
to enter into this Agreement.

          3.2.   AUTHORITY TO EXECUTE AND PERFORM AGREEMENTS.  Such party has
the full legal right and power and all authority and approvals required to enter
into, execute and deliver this Agreement and to perform fully its obligations
hereunder and thereunder, and this Agreement has been duly executed and
delivered and is the valid and binding obligation of such party enforceable in
accordance with its terms.  Such party has obtained the necessary approval of
its Board of Directors and, to the extent necessary, stockholders with respect
to the transactions contemplated hereby.

          3.3.   NO BREACH.  The execution, delivery and performance of this
Agreement and the consummation of the transactions contemplated hereby and
thereby will not (i) violate any provision of the Certificate of Incorporation,
as amended, or By-laws of such party; (ii) give any other contracting party any
right to assert any claim or liability against any other party or to assert that
any other party has assumed any liability of Seller except as expressly
contemplated hereby; (iii) violate any order, judgment, injunction, award


                                      - 2 -

<PAGE>

or decree of any court, arbitrator or governmental or regulatory body against,
or binding upon, such party or upon the securities, properties, assets or
business of such party; (iv) to the best of such party's knowledge, violate any
statute, law or regulation of any jurisdiction as such statute, law or
regulation relates to such party or to the Partnership Interest; (v) violate any
Permit; (vi) require the approval or consent of any foreign, federal, state,
local or other governmental or regulatory body or the approval or consent of any
other person; or (vii) result in the creation of any lien or other encumbrance
on the Partnership Interest.

     4.   ADDITIONAL REPRESENTATIONS AND WARRANTIES OF PROTYDE.

          4.1.   ACCREDITED INVESTOR.  Protyde is an "accredited investor" as
defined in Regulation D under the Securities Act.

          4.2.   EXCHANGE ACT REPORTS.  Protyde has received and read or
reviewed and is familiar with 34 Act Reports (as defined in Section 5.2 below).

          4.3.   INQUIRIES.  Protyde has had an opportunity to ask questions of
and receive answers from Bigmar, or a person or persons acting on Bigmar's
behalf, concerning risks and merits of the Warrants and the Warrant Shares.

          4.4.   ABSENCE OF REGISTRATION.  Protyde understands that the Warrants
and the Warrant Shares have not been registered under the Securities Act or
under the securities laws of any state or other jurisdiction in reliance upon
exemptions for private offerings, and that, while Bigmar may in the future
register the Warrant Shares, it is under no obligation to do so, and Protyde
further understands that it is acquiring the Warrants without being furnished
any offering literature or prospectus other than the 34 Act Reports referred to
in Section 4.2 above.

          4.5.   INVESTMENT INTENT.  Protyde represents that the Warrants are
being acquired solely for Protyde's own account, for investment and not with a
view to or for the resale, distribution, subdivision, or fractionalization
thereof other than a distribution to the stockholders of Protyde on liquidation
of Protyde.  Other than such a distribution, Protyde has no present plans to
enter into any contract, undertaking, agreement, or arrangement relating
thereto.

          4.6.   RESTRICTED RESALE.  Protyde acknowledges and is aware that
there are substantial restrictions on the transferability of the Warrants and
the Warrant Shares; the Warrants and the Warrant Shares cannot be resold unless
the Warrant Shares are registered under the Securities Act and any applicable
securities law of any state or other jurisdiction, or an exemption from
registration is available; Protyde has no rights to require that the Warrant
Shares be registered under the Securities Act; and unless the Warrant Shares are
so registered or an exemption therefrom is available to Protyde, there will be
no public market for the Warrant Shares.

          4.7.   INVESTMENT EXPERIENCE.  Protyde has such knowledge and
experience in financial and business matters that they are capable of evaluating
the relative risks and merits of the Warrants and the Warrant Shares.


                                      - 3 -

<PAGE>

          4.8    EXECUTIVE OFFICES.  Protyde's principal executive offices are
c/o Marathon Investments, LLC, 13260 Spencer Road, Hemlock, MI 48626.

     5.   ADDITIONAL REPRESENTATIONS AND WARRANTIES OF BIGMAR.

     Bigmar represents and warrants to Protyde as follows:

          5.1.   CAPITALIZATION.  The authorized capital stock of Bigmar
consists of (i) 15,000,000 shares of Common Stock, $0.001 par value, of which
3,985,000 shares were validly issued and outstanding as of April 11, 1997 and
(ii) 5,000,000 shares of Preferred Stock, $0.001 par value, none of which are
outstanding.  Except as disclosed in Bigmar's Report on Form 10-K for its fiscal
year ended December 31, 1996 (the "Form 10-K"), there are outstanding no rights
of subscription, warrants, calls, options, contracts or other agreements or
commitments of any kind to acquire from Bigmar any shares of capital stock of
Bigmar or any securities convertible into or exchangeable for such shares and
there are no contracts, commitments, understandings, arrangements or
restrictions by which Bigmar is bound to issue any additional shares of its
capital stock or any other securities, other than employee options issued in the
ordinary course of business.  The issuance of the Warrants and the Warrant
Shares has been duly authorized by all necessary corporate action and, when
issued in accordance with the terms of this Agreement, will be duly and validly
issued and fully paid and nonassessable, and will have been issued in compliance
with applicable securities laws, free and clear of any lien or encumbrance.

          5.2    SECURITIES FILINGS.  Bigmar has heretofore delivered to Protyde
true, correct and complete copies of the Form 10-K and Bigmar's Form 10-Q for
the period ended March 31, 1997 (such reports, collectively the "34 Act
Reports").  The 34 Act Reports, taken as a whole, do not contain any untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements made, in the context in which
made, not false or misleading.  The Form 10-K contains the audited balance sheet
of Bigmar as of December 31, 1996, and the related statement of income and
retained earnings for the twelve months then ended, certified by Bigmar's
independent public accountants and the other 34 Act Report contains the
unaudited balance sheet of Bigmar as of March 31, 1997 and the related income
statement for the period then ended; such financial statements have been
prepared in accordance with generally accepted accounting principles and fairly
present the financial position of Bigmar as of said balance sheet dates and the
results of its operations for the periods indicated, except that the unaudited
financial statements are subject to those adjustments which would arise in an
audit (the effect of which would not, individually or in the aggregate, be
materially adverse) and do not contain the notes required under generally
accepted accounting principles.

          5.3    COMPLIANCE WITH SECURITIES LAWS: NASDAQ LISTING.  Bigmar has
not offered and not authorized anyone to offer the Warrants or the Warrant
Shares so as to cause the issuance of the Warrants and the Warrant Shares to
violate the provisions of Section 5 of the Securities Act or any applicable
state law regarding the issuance of securities, or offered any other securities
for issuance or solicited any offer to acquire any of the same form, or
otherwise approached or negotiated with respect thereto with, anyone in such a
way as to cause the issuance of the Warrants or the Warrant Shares to fail to be
exempt from


                                      - 4 -
<PAGE>

registration requirements of the Securities Act and from any applicable state
laws.  Upon exercise of a Warrant, the Warrant Shares will be listed on the
Nasdaq Small Cap Market.

     6.   TERMINATION OF CONTRACTS.

          6.1.   SALES AND MARKETING AGREEMENT.  The Partnership and Protyde
hereby agree, pursuant to Section 10.2 of the Sales and Marketing Agreement
between the Partnership and Protyde dated October 27, 1995 (the "Sales and
Marketing Agreement") to terminate the Sales and Marketing Agreement effective
on the date hereof, without payment of consideration to either party.

          6.2.   MANUFACTURING AGREEMENT.  The Partnership and Bigmar hereby
agree, pursuant to Section 9.2 of the Manufacturing Agreement between the
Partnership and Bigmar dated October 27, 1995 (the "Manufacturing Agreement") to
terminate the Manufacturing Agreement effective on the date hereof, without
payment of consideration to either party.

     7.   MISCELLANEOUS.

          7.1.   PUBLICITY.  No publicity release or announcement concerning
this Agreement or the transactions contemplated hereby shall be made without
advance approval thereof by Protyde and Bigmar.

          7.2.   ENTIRE AGREEMENT.  This Agreement [and the Registration Rights
Agreement] contain the entire agreement among the parties with respect to the
purchase of the Partnership Interest and related transactions, and supersedes
all prior agreements, written or oral, with respect thereto.

          7.3.   WAIVERS AND AMENDMENTS; NON-CONTRACTUAL REMEDIES;  PRESERVATION
OF REMEDIES.  This Agreement may be amended, superseded, canceled, renewed or
extended, and the terms hereof may be waived, only by a written instrument
signed by the parties or, in the case of a waiver, by the party waiving
compliance.  No delay on the part of any party in exercising any right, power or
privilege hereunder shall operate as a waiver thereof nor shall any waiver on
the part of any party of any such right, power or privilege, nor any single or
partial exercise of any such right, power or privilege, preclude any further
exercise thereof or the exercise of any other such right, power or privilege.
The rights and remedies herein provided are cumulative and are not exclusive of
any rights or remedies that any party may otherwise have at law or in equity.
The rights and remedies of any party based upon, arising out of or otherwise in
respect of any inaccuracy in or breach of any representation, warranty, covenant
or agreement contained in this Agreement shall in no way be limited by the fact
that the act, omission, occurrence or other state of facts upon which any claim
of any such inaccuracy or breach is based may also be the subject matter of any
other representation, warranty, covenant or agreement contained in this
Agreement (or in any other agreement between the parties) as to which there is
not inaccuracy or breach.

          7.4.   GOVERNING LAW.  This Agreement shall be governed and construed
in accordance with the laws of the State of Delaware.


                                      - 5 -

<PAGE>

          7.5.   ENFORCEABILITY IN JURISDICTIONS; CONSENT.  The parties hereto
intend to and hereby confer jurisdiction to enforce the provisions of this
Agreement upon the courts of the State of Illinois.  The parties hereto hereby
acknowledge and agree that any breach of their respective obligations under this
Agreement or any other agreement executed in connection herewith shall be deemed
to have occurred at Chicago, Illinois and that such party has purposely
established minimum contact in Chicago, Illinois within the meaning of all
applicable law.  Each of the parties hereto consents to the jurisdiction of said
court or courts in Chicago, Illinois and to service of process by certified
mail, return receipt requested, or by any other manner provided by law.  Any
legal action, suit or proceeding arising out of or relating to such claim may be
instituted against a party in any state or federal court located in Chicago,
Illinois and each such party agrees not to assert, by way of motion, as a
defense, or otherwise, in any such action, suit or proceeding, any claim that it
is not subject personally to the jurisdiction of such courts that the action,
suit or proceeding is brought in an inconvenient forum, that the venue of the
action, suit or proceeding is improper or that this Agreement or the subject
matter hereof may not be enforced in or by such court.

          7.6.   BINDING EFFECT; NO ASSIGNMENT.  This Agreement shall be binding
upon and inure to the benefit of the parties and their respective successors and
legal representatives.  This Agreement is not assignable except by operation of
law or by Bigmar to any of its affiliates.

          7.7.   COUNTERPARTS.  This Agreement may be executed by the parties
hereto in separate counterparts, each of which when so executed and delivered
shall be an original, but all such counterparts shall together constitute one
and the same instrument.  Each counterpart may consist of a number of copies
hereof each signed by less than all, but together signed by all of the parties
hereto.

          7.8.   HEADINGS.  The headings in this Agreement are for reference
only, and shall not affect the interpretation of this Agreement.



     [The Remainder of This Page Intentionally Left Blank]


                                      - 6 -

<PAGE>

     IN WITNESS WHEREOF, the undersigned have executed this Assignment and
Assumption of Partnership Agreement as of the date first above written.


                                             PROTYDE ONCOLOGY THERAPEUTICS, INC.


                                             By:  /s/ Cynthia R. May
                                                  -----------------------------
                                             Title:


                                             BIGMAR THERAPEUTICS, INC.


                                             By:  /s/ Michael K. Medors
                                                  -----------------------------
                                             Title: CFO


                                             PROTYDE PHARMACEUTICAL, INC.


                                             By:  /s/ Cynthia R. May
                                                  -----------------------------
                                             Title:


                                             BIGMAR, INC.



                                             By:  /s/ John Tramontana
                                                  -----------------------------
                                             Title:  President


                                      - 7 -

<PAGE>

                                        PROTYDE-BIGMAR THERAPEUTICS

                                        BY:  PROTYDE ONCOLOGY
                                             THERAPEUTICS, INC., General Partner


                                             By:  /s/ Cynthia R. May
                                                  ----------------------------
                                             Title:


                                        BY:  BIGMAR THERAPEUTICS, INC.
                                             General Partner


                                             By:  /s/  Michael K. Medors
                                             ---------------------------
                                             Title:  CFO


                                      - 8 -
<PAGE>
                                                                      EXHIBIT A

THE WARRANTS REPRESENTED BY THIS CERTIFICATE AND THE OTHER SECURITIES ISSUABLE
UPON EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
AS AMENDED, AND MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO A REGISTRATION
STATEMENT UNDER SUCH ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO
COUNSEL FOR THE ISSUER THAT AN EXEMPTION FROM REGISTRATION UNDER SUCH ACT IS
AVAILABLE.  THE TRANSFER OR EXCHANGE OF THE WARRANTS REPRESENTED BY THIS
CERTIFICATE ARE FURTHER RESTRICTED AS DESCRIBED HEREIN.

                                     BIGMAR, INC.

                            COMMON STOCK PURCHASE WARRANTS

                                    500,000 SHARES

              EXERCISABLE UNTIL 5:00 P.M., NEW YORK TIME, JULY 24, 2002

    This Warrant Certificate certifies that Protyde, Inc. or its registered 
assigns, is the registered holder of Warrants to purchase initially up to 
500,000 fully-paid and non-assessable shares (the "Warrant Shares") of common 
stock, $0.001 par value ("Common Stock") of Bigmar, Inc., a Delaware 
corporation (the "Company"), at any time from July 24, 1997 until 5:00 p.m. 
New York time on July 24, 2002 (the "Expiration Date"), at the initial 
exercise price (the "Exercise Price") of $5.00 per share of Common Stock, 
subject to the conditions set forth herein.  The number of Warrant Shares 
issuable hereunder and the Exercise Price are each subject to adjustment as 
provided herein.  No Warrant may be exercised after 5:00 p.m., New York time, 
on the Expiration Date, after which time all Warrants evidenced hereby, 
unless exercised prior thereto, shall be void.

1.  CERTAIN DEFINITIONS.  As used herein the following terms, unless the context
otherwise requires, have the following respective meanings:

    1.1  The term "Company" shall include Bigmar, Inc. and any corporation that
shall succeed or assume the obligations of Bigmar, Inc. hereunder.

    1.2  The terms "Warrant" or "Warrants" mean these Warrants and any other
warrant or warrants issued in exchange or substitution for, or upon partial
exercise of, these Warrants.

    1.3  The term "Holder" means the registered holder(s) of this Warrant
Certificate.

2.  EXERCISE OF WARRANTS.

    2.1  Warrants may be exercised by the Holder hereof, at any time until 5:00
p.m. New York time on the Expiration Date, as to the whole or any lesser number
of the Warrant Shares covered hereby, by the surrender of this Warrant
Certificate (with the election at the end hereof duly executed) to the Company
at its main office at 6660 Doubletree Avenue, Columbus, OH 43229 ("Main
Office"), or at such other place as may be designated in writing by the Company,
together with a certified or bank check payable to the order of the Company in
an amount equal to the Exercise Price multiplied by the number of Warrant Shares
for which such Warrants are being exercised.

    2.2  Upon each exercise of the Holder's right to purchase Warrant Shares,
the Holder shall be deemed to be the holder of record of the Warrant Shares
issuable upon such exercise, notwithstanding that the transfer books of the
Company shall then be closed of certificates representing such Warrant


                                         -9-
<PAGE>

Shares shall not then have been actually delivered to the Holder.  As soon as
practicable after each such exercise of a Warrant, the Company shall issue and
deliver to the Holder a certificate or certificates for the Warrant Shares
issuable upon such exercise, registered in the name of the Holder of its
designee.  If a Warrant should be exercised in part only, the Company shall,
upon surrender of the Warrant Certificate evidencing such Warrant for
cancellation, execute and deliver a new Warrant Certificate evidencing the right
of the Holder to purchase the balance of the Warrant Shares (or portions
thereof) subject to purchase hereunder.

    2.3  The issuance of any shares or other securities upon the exercise of
Warrants and the delivery of certificates or other instruments representing such
shares or other securities shall be made without charge to the Holder for any
tax or other charge (other than payment of the Exercise Price) in respect of
such issuance.  The Company shall not, however, be required to pay any tax that
may be payable in respect of any transfer involved in the issue and delivery of
any certificate in a name other than that of the Holder, and the Company shall
not be required to issue or deliver any such certificate unless and until the
person or persons requesting the issue thereof shall have paid to the Company
the amount of such tax or shall have established to the satisfaction of the
Company that such tax has been paid.

3.  ADJUSTMENT OF EXERCISE PRICE.  Subject to the provisions of this Section 3,
the Exercise Price in effect from time to time shall be subject to adjustment as
follows:

    3.1  If the Company shall at any time after the date hereof (i) declare a
dividend on the outstanding Common Stock payable in shares of
its Common Stock, (ii) subdivide the outstanding Common Stock, (iii) combine the
outstanding Common Stock into a smaller number of shares, or (iv) issue any
shares of its Common Stock by reclassification in connection with a
consolidation or merger in which the Company is the continuing corporation,
then, in each such case, the Exercise Price in effect and the number of Warrant
Shares issuable upon exercise hereof at the time of the record date for such
dividend or of the effective date of such subdivision, combination or
reclassification, shall be proportionately adjusted so that the Holder hereof
after such time shall be entitled to receive upon exercise hereof the aggregate
number and kind of shares that such Holder would have owned upon exercise of
this Warrant immediately before such time and been entitled to receive by virtue
of such dividend, subdivision, combination or reclassification.

    3.2  If the Company shall distribute to all holders of Common Stock
(including any such distribution made to the shareholders of the Company in
connection with a consolidation or merger in which the Company is the continuing
corporation) (i) evidences of its indebtedness, cash or assets (other than
ordinary cash dividends paid out of the net profits of the Company for its most
recent fiscal year), (ii) rights, options or warrants to subscribe for or
purchase Common Stock, or (iii) any equity securities of the Company (other than
Common Stock), including any securities convertible into or exchangeable for
shares of Common Stock, then, in each case, the Exercise Price shall be adjusted
by multiplying the Exercise Price in effect immediately before the record date
for the determination of shareholders entitled to receive such distribution by a
fraction, the numerator of which shall be the Current Market Price (as
determined pursuant to Section 3.6 hereof) per share of Common Stock on such
record date, less the fair market value (as determined in good faith by the
Board of Directors of the Company, whose determination shall be conclusive
absent manifest error) of the portion of the evidences of indebtedness or assets
so to be distributed, or of such securities, rights, options, or warrants, or
the amount of such cash, applicable to one share, and the denominator of which
shall be such Current Market Price per share of Common Stock.  Such adjustment
shall become effective at the close of business on such record date.

    3.3  In any case in which this Section 3 shall require that an adjustment
in the number of Warrant Shares be made effective as of a record date for a
specified event (an "Event"), the Company may elect to defer, until the
occurrence of such Event, issuing to the Holder, if the Holder exercised this
Warrant after such record date, the shares of Common Stock, if any, issuable
upon such exercise over and above the number of Warrant Shares, if any, issuable
upon such exercise on the basis of the number of Warrant Shares in effect prior
to such adjustment; provided, however, that the Company shall deliver to the
Holder a due bill or other appropriate instrument evidencing the Holder's right
to receive such additional shares upon the occurrence of the Event requiring
such adjustment.


                                         -10-
<PAGE>

    3.4  Whenever there shall be an adjustment as provided in this Section 3,
the Company shall within 15 days thereafter cause written notice thereof to be
sent by registered or certified mail, postage prepaid, to the Holder, at its
address as it shall appear in the Warrant Register, which notice shall be
accompanied by an officer's certificate setting forth the number of Warrant
Shares issuable hereunder and the Exercise Price thereof after such adjustment
and setting forth a brief statement of the facts requiring such adjustment and
the computation thereof, which officer's certificate shall be conclusive
evidence of the correctness of any such adjustment absent manifest error.

    3.5  All calculations under this Section 3 shall be made to the nearest
cent or the nearest one-thousandth of a share, as the case may be.  No
adjustment in the Exercise Price shall be required if such adjustment is less
than $0.05; provided, however, that any adjustments that by reason of this
Section 3.5 are not required to be made shall be carried forward and taken into
account in any subsequent adjustment.  The Company shall not be required to
issue fractions of shares of Common Stock or other capital stock of the Company
upon the exercise of Warrants.  If any fraction of a share would be issuable on
the exercise of Warrants, the Company shall purchase such fraction for an amount
in cash equal to the same fraction of the Current Market Price (as hereinafter
defined) of such share of Common Stock on the date of exercise of the Warrants.

    3.6  The Current Market Price per share of Common Stock as of any date
shall be the average of the daily closing prices for the 20 consecutive trading
days immediately preceding the date in question.  The closing price for each day
shall be the last reported sales price regular way or, in case no such reported
sale takes place on such day, the closing bid price regular way, in either case
on the principal national securities exchange (including, for purposes hereof,
the Nasdaq National Market or Small Cap Market) on which the Common Stock is
listed or admitted to trading or, if the Common Stock is not listed or admitted
to trading on any national securities exchange, the highest reported bid price
of the Common Stock as furnished by the National Association of Securities
Dealers, Inc. through Nasdaq, or a similar organization if Nasdaq is no longer
reporting such information.  If on any such date the Common Stock is not listed
or admitted to trading on any national securities exchange and is not quoted by
Nasdaq or any similar organization, the fair value of a share of Common Stock on
such date, as determined in good faith by the Board of Directors of the Company,
whose determination shall be conclusive absent manifest error, shall be used.

4.  MERGERS; REORGANIZATIONS.

    4.1  In each case of a consolidation with or merger of the Company with 
or into another corporation (other than a merger or consolidation in which 
the Company is the surviving or continuing corporation and that does not 
result in any reclassification of the outstanding shares of Common Stock or 
the conversion of such outstanding shares of Common Stock into shares of 
other stock or other securities or property), or in case of any sale, lease 
or conveyance to another corporation of the property and assets of any nature 
of the Company as an entirety or substantially as an entirety (such actions 
being hereinafter collectively referred to as "Reorganizations"), there shall 
thereafter be deliverable upon exercise of the Warrants (in lieu of the 
number of Warrant Shares theretofore deliverable) the kind and amount of 
shares of stock or other securities or property to which a holder of the 
number of Warrant Shares that would otherwise have been deliverable upon the 
exercise hereof upon such Reorganization if the Warrants had been exercised 
in full immediately before such Reorganization.  In case of any 
Reorganization, appropriate adjustment, as determined in good faith by the 
Board of Directors of the Company, shall be made in the application of the 
provisions herein set forth with respect to the rights and interests of the 
Holder so that the provisions set forth herein shall thereafter be 
applicable, as nearly as possible, in relation to any shares or other 
property thereafter deliverable upon exercise of the Warrants.  Any such 
adjustment shall be made by and set forth in a supplemental agreement between 
the Company, or any successor thereto, and the Holder and shall for all 
purposes hereof conclusively be deemed to be an appropriate adjustment.  The 
Company shall not effect any such Reorganization unless upon or before the 
consummation thereof the successor corporation or, if the Company shall be 
the surviving corporation in any such Reorganization and is not the issuer of 
the shares of stock or other securities or property to be delivered to 
holders of shares of the Common Stock outstanding at the effective time 
thereof, then such issuer, shall assume by written instrument the obligation 
to deliver to the Holder such shares of stock, securities, cash or other 
property as the Holder shall be entitled to purchase in accordance with the 
foregoing provisions.

                                         -11-
<PAGE>

    4.2  In each case of a reclassification or change of the shares of Common
Stock issuable upon exercise of the Warrants (other than a change in par value
or from no par value to a specified par value, or as a result of a subdivision
or combination, but including any change in the shares into two or more classes
or series of shares), and in each case of any consolidation or merger of another
corporation into the Company in which the Company is the continuing corporation
and in which there is a reclassification or change (including a change to the
right to receive cash or other property) of the shares of Common Stock (other
than a change in par value, or from no par value to a specified par value, or as
a result of a subdivision or combination, but including any change in the shares
into two or more classes or series of shares), the Holder shall have the right
thereafter to receive upon exercise of the Warrants solely the kind and amount
of shares of stock and other securities, property, cash, or any combination
thereof receivable upon such reclassification, change, consolidation, or merger
by a holder of the number of shares of Common Stock for which the Warrants might
have been exercised immediately before such reclassification, change,
consolidation, or merger.  Thereafter, appropriate provision shall be made for
adjustments that shall be as nearly equivalent as practicable to the adjustments
required by Section 3.

5.  NOTICE OF CERTAIN EVENTS.  In case at any time the Company shall propose:

         (a)  to pay any dividend or make any distribution on shares of Common
Stock in shares of Common Stock or make any other distribution (other than
regularly scheduled cash dividends that are not in a greater amount per share
than the most recent such cash dividend) to all holders of Common Stock; or

         (b)  to issue any rights, warrants or other securities to all holders
of Common Stock entitling them to purchase any additional shares of Common Stock
or any other rights, warrants or other securities; or

         (c)  to effect any reclassification or change of outstanding shares of
Common Stock or any consolidation, merger, sale, lease or conveyance of property
described in Section 4; or

         (d)  to effect any liquidation, dissolution or winding-up of the
Company;

then, and in any one or more of such cases, the Company shall give written
notice thereof by registered or certified mail, postage prepaid, to the Holder
at the Holder's address as it shall appear in the Warrant Register, mailed at
least 15 days before (i) the date as of which the holders of record of shares of
Common Stock to be entitled to receive any such dividend, distribution, rights,
warrants or other securities are to be determined or (ii) the date on which any
such reclassification, change of outstanding shares of Common Stock,
consolidation, merger, sale, lease, conveyance of property, liquidation,
dissolution or winding-up is expected to become effective and the date as of
which it is expected that holders of record of shares of Common Stock shall be
entitled to exchange their shares for securities or other property, if any,
deliverable upon such reclassification, change of outstanding shares,
consolidation, merger, sale, lease, conveyance of property, liquidation,
dissolution or winding-up.

6.  WARRANT REGISTER; TRANSFERS OF WARRANTS.

    6.1  This Warrant Certificate and any new Warrant Certificate issued upon
the transfer or exercise in part of any Warrants shall be numbered and shall be
registered in a Warrant Register as it is issued.  The Company shall be entitled
to treat the holder of this Warrant Certificate registered on the Warrant
Register as the owner in fact of the Warrants evidenced hereby for all purposes,
shall not be bound to recognize any equitable or other claim to or interest in
such Warrants on the part of any other person, and shall not be liable for any
registration or transfer of a Warrant Certificate that is registered or to be
registered in the name of a fiduciary or the nominee of a fiduciary unless made
with the actual knowledge that a fiduciary or nominee is committing a breach of
trust in requesting such registration or transfer, or with the knowledge or such
facts that its participation therein amounts to bad faith.  Warrants shall be
transferable only in the Warrant Register upon delivery of the Warrant
Certificate evidencing such Warrants duly endorsed by the Holder or by his or
its duly authorized attorney or representative, or accompanied by proper
evidence of succession, assignment, or authority to transfer.  In all cases of
transfer by an attorney, executor, administrator, guardian or other legal
representative, duly authenticated evidence of his or its authority shall be
produced.

    6.2  Upon any registration of transfer, the Company shall deliver to the
person entitled thereto


                                         -12-
<PAGE>

a new Warrant Certificate of like tenor and evidencing in the aggregate a like
number of Warrants in exchange for this Warrant Certificate, subject to the
limitations provided herein.  This Warrant Certificate may be exchanged, at the
option of the Holder hereof, for another Warrant Certificate, or other Warrant
Certificates of different denominations, of like tenor and representing in the
aggregate the right to purchase a like number of Warrant Shares (or portions
thereof), upon surrender to the Company or its duly authorized agent.
Notwithstanding the foregoing, The Company shall have no obligation to cause
Warrants to be transferred on its books to any person if, in the reasonable
opinion of counsel to the Company, such transfer does not comply with the
provisions of the Securities Act of 1933, as amended (the "Act"), and the rules
and regulations thereunder, or with any other restrictions set forth herein.

    6.3  The Warrants and Warrant Shares shall be subject to a stop transfer
order and the certificate or certificates evidencing the Warrant Shares shall
bear the following legend:

"THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, AND SUCH SHARES MAY NOT BE OFFERED OR SOLD
EXCEPT PURSUANT TO A REGISTRATION STATEMENT UNDER SUCH ACT OR AN OPINION OF
COUNSEL REASONABLY SATISFACTORY TO COUNSEL FOR THE ISSUER THAT AN EXEMPTION FROM
REGISTRATION UNDER SUCH ACT IS AVAILABLE."

7.  AUTHORIZED SHARES.  The Company shall at all times reserve and keep
available out of its authorized and unissued Common Stock, solely for the
purpose of providing for the exercise of the Warrants, such number of shares of
Common Stock as shall, from time to time, be sufficient therefor.  The Company
covenants that all shares of Common Stock issuable upon exercise of the Warrants
shall, upon receipt by the Company of the full payment therefor, be validly
issued, fully paid, nonassessable, and free of preemptive rights.

8.  MISCELLANEOUS.

    8.1  Upon receipt of evidence satisfactory to the Company of the loss,
theft, destruction or mutilation of any Warrant Certificate (and upon surrender
of any Warrant Certificate if mutilated), upon issuance of an indemnity bond if
required by the Company, and upon reimbursement of the Company's incidental
expenses, the Company shall execute and deliver to the Holder hereof a new
Warrant Certificate of like date, tenor and denomination.

    8.2  The Holder hereof shall not have, solely on account of such status, 
any rights of a stockholder of the Company, either at law or in equity, or to 
any notice of meetings of stockholders or of any other proceedings of the 
Company, except as provided herein.

    8.3  This Warrant Certificate and the Warrants shall be construed in
accordance with the laws of the State of Delaware applicable to contracts made
and performed within such State, without regard to principles of conflicts of
law.

IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be duly
executed as an instrument under seal as of July 24, 1997

BIGMAR, INC.



By: /s/ John Tramontana
    -------------------------
    Title: President


                                         -13-
<PAGE>

                                 FORM OF SUBSCRIPTION
                      (To be signed only on exercise of Warrant)

TO Bigmar, Inc.:

    The undersigned, the holder of the within Warrant, hereby irrevocably
elects to exercise this Warrant for, and to purchase thereunder, ____________
shares of Common Stock of Bigmar, Inc. and herewith makes payment of $ _________
therefor, and requests that the certificates for such shares be issued in the
name of, and delivered to
____________________________________________________________________, whose
address is _________________________________________________________.


Dated: ____________
                                       ----------------------------------------
                                       (Signature must conform to the name of
                                       holder as specified on the face of the
                                       Warrant)

                                       ----------------------------------------
                                            (Address)


                             ----------------------------

                                  FORM OF ASSIGNMENT
                     (To be signed only on transfer of Warrant)



    For value received, the undersigned hereby sells, assigns, and transfers
unto __________________________________ the right represented by the within
Warrant to purchase ___________________________ shares of Common Stock of
Bigmar, Inc. to which the within Warrant relates, and appoints 
_________________ attorney to transfer such right on the books of Bigmar, 
Inc. with full power of substitution in the premises.


Dated: ____________
                                       ----------------------------------------
                                       (Signature must conform to name of the
                                       holder as specified on the face of the
                                       Warrant)

                                       ----------------------------------------
                                            (Address)


                                         -14-