Exhibit 5.1

                                                     February 2, 2005



Phibro Animal Health Corporation
65 Challenger Road
Ridgefield, New Jersey  07660

      Re:   Phibro Animal Health Corporation Registration Statement on Form S-4


Ladies and Gentlemen:

            We have acted as counsel to Phibro Animal Health Corporation, a New
York corporation (the "Company"), and the Designated Guarantors (as hereinafter
defined), in connection with the public offering of 127,491 units, consisting of
$103.207 million principal amount of new 13% Senior Secured Notes due 2007 (the
"New U.S. Notes") of the Company and $24.284 million principal amount of new 13%
Senior Secured Notes due 2007 (the "New Dutch Notes" and together with the New
U.S. Notes, the "New Notes") of Philipp Brothers Netherlands III B.V. (the
"Dutch Issuer"). The New U.S. Notes will be guaranteed, on a senior secured
basis pursuant to the guarantees (the "Domestic Guarantees" and, together with
the New Notes, the "New Domestic Securities") by Phibro-Tech, Inc., a Delaware
corporation, Prince Agriproducts, Inc., a Delaware corporation, Koffolk, Inc., a
Delaware corporation, C P Chemicals, Inc., a New Jersey corporation, Phibrochem,
Inc., a New Jersey corporation, Phibro Chemicals, Inc., a New York corporation,
Phibro Animal Health U.S., Inc., a Delaware corporation, Phibro Animal Health
Holdings, Inc., a Delaware corporation, and Western Magnesium Corp., a
California corporation (collectively, the "Domestic Guarantors"). We have also
acted as special New York counsel to the Dutch Issuer in connection with the New
Dutch Notes and to Phibro Animal Health SA ("Phibro Belgium") and the Company in
connection with their guarantees thereof. The New Domestic Securities, together
with the New Dutch Note and the guarantees thereof by the Company and Phibro
Belgium are referred to collectively as the "New Securities"). The seven
Domestic Guarantors that are incorporated under the laws of the States of New
York, Delaware or New Jersey are collectively referred to as the "Designated
Guarantors." The New Securities are to be issued pursuant to an exchange offer
(the "Exchange Offer") in exchange for a like principal amount of the issued and
outstanding 13% Senior Secured Notes due 2007 of the Company and of the Dutch
Issuer (collectively, the "Old Securities") under an Indenture, dated as of
October 21, 2003 as supplemented as of December



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February 2, 2005
Page 2


21, 2004 (the "Indenture"), by and among the Company, the Dutch Issuer, the
Domestic Guarantors and HSBC Bank USA, National Association, as trustee (the
"Trustee"), as contemplated by the Registration Rights Agreements dated October
21, 2003 and December 21, 2004 (the "Registration Rights Agreement"), by and
among the Company, the Dutch Issuer, the Domestic Guarantors and Jefferies &
Company, Inc.

            This opinion is being furnished to you in accordance with the
requirements of Item 601(b)(5) of Regulation S-K under the Securities Act of
1933, as amended (the "Act"), in connection with the filing of the Registration
Statement (as hereinafter defined) and for no other purpose.

            In connection with this opinion, we have examined originals or
copies, certified or otherwise identified to our satisfaction, of (i) the
Registration Statement on Form S-4 (File No. 333-122063) as filed with the
Securities and Exchange Commission (the "Commission") on January 12, 2005 under
the Act, and Amendment No.1 thereto as filed with the Commission on February _,
2005 (such Registration Statement, as so amended, being hereinafter referred to
as the "Registration Statement"); (ii) an executed copy of the Registration
Rights Agreement; (iii) an executed copy of the Indenture; (iv) the Certificate
of Incorporation of the Company, and the Certificate of Incorporation of each of
the Designated Guarantors, each as amended to date; (v) the By-Laws of the
Company, and the By-Laws of each of the Designated Guarantors, each as amended
to date; (vi) Certificates issued by the Secretary of State of the States of New
York, Delaware and New Jersey, certifying the existence of the Company and each
of the Designated Guarantors and its respective authority to transact business
in its state of incorporation; (vii) certain resolutions adopted by the Board of
Directors and shareholders of the Company, relating to the Exchange Offer, the
issuance the New Securities issued by it, the Indenture and related matters,
certified by the Secretary of the Company as true and complete; (viii) certain
resolutions adopted by the Board of Directors and shareholders of each of the
Designated Guarantors relating to, among other things, the issuance of the
Domestic Guarantees by the Designated Guarantors, certified by the Secretary of
each of the applicable Designated Guarantors as true and complete; (ix) the Form
T-1 of the Trustee filed as an exhibit to the Registration Statement; and (x)
the form of the New Notes (including the form of Domestic Guarantees). We have
also examined originals or copies, certified or otherwise identified to our
satisfaction, of such records of the Company and the Designated Guarantors and
such agreements, certificates of public officials, certificates of officers or
other representatives of the Company, the Designated Guarantors and others, and
such other documents, certificates and records as we have deemed necessary or
appropriate as a basis for the opinions set forth herein.

            In rendering these opinions we have assumed (i) the genuineness of
all signatures, the legal capacity of all natural persons, the authenticity of
all documents submitted to us as originals, the conformity to original documents
of all documents submitted to us as certified, conformed or photostatic copies
or by electronic means and the authenticity of the originals of such latter
documents; (ii) that all parties other than the Company and the Designated
Guarantors have the power, corporate or otherwise, to enter into and perform all
obligations under all



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February 2, 2005
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documents we have examined in connection with these opinions (the "Examined
Documents"); (iii) that all the Examined Documents have been duly authorized by
all requisite action, corporate or other, by each part thereto (other than the
Company and the Domestic Guarantees), and have been duly authorized by all
requisite action, corporate or others, and executed and delivered by, and each
of them constitutes the legally valid and binding obligation of, such other
parties, as applicable, enforceable against such other parties in accordance
with their respective terms; (iv) that the resolutions of the Board of Directors
and shareholders of the Company and the Designated Guarantors in connection with
the Purchase Agreement dated October 21, 2003 and December 21, 2004 between the
Company, the Dutch Issuer and Jefferies & Company, Inc. and the sale of the Old
Securities have not been rescinded and revoked, (v) the satisfaction of all the
requirements with respect to the execution, delivery and performance of the New
Securities and other documents securing any thereof by each party to each
document (other than the Company and the Designated Guarantors); and (vi) that
each part to any of the documents (other than the Company and the Designated
Guarantors) has complied with all laws, rules, orders and regulations applicable
to it other than Applicable Laws (defined below) and has taken or obtained all
actions, consents, approvals, authorizations, filings, exemptions,
registrations, qualifications, orders and notations necessary under all
applicable laws, rules, regulations and orders other than the Applicable Laws
("Foreign Laws") (without resort to principles of estoppel, apparent authority,
waiver or the like) to bind it under the documents to which it is a party,
including without limitation the issuance and sale of the New Dutch Notes and
the execution, delivery and performance of each Document to which it is a party
and the consummation of the transactions contemplated by the Registration Rights
Agreement. We have also assumed (i) that the execution, delivery and performance
of the Guarantees and the Indenture by each of the Guarantors incorporated under
the laws of California will not violate any provisions of the laws of such
state, (ii) the validity, binding effect and enforceability of the Indenture and
the Guarantees of the Guarantors incorporated under the laws of California under
the laws of such state, and (iii) that the laws of such jurisdictions would not
affect any of the conclusions stated herein. As to any fact material to the
opinions expressed herein which we have not independently established or
verified, we have relied upon statements and representations of officers and
other representatives of the Company, the Dutch Issuer, the Guarantors and
others. In addition, we have assumed that there will be no changes in applicable
law between the date of this opinion and the date of issuance and delivery of
the New Securities.

            Members of our firm are admitted to the bar in the State of New York
(without regard to conflict of laws) and we express no opinion with regard to
any matter which may be governed by any law other than the federal law of the
United States of America, the laws of the State of New York and, to the extent
necessary to render this opinion, the Delaware corporate law and the New Jersey
corporate law. Such laws as to which we express an opinion are referred to as
"Applicable Laws." We have assumed for purposes of this letter, that the
internal laws of the State of New York in each case without regard to conflict
of laws principles would apply to each of the documents and to each other
document relevant to our opinions, notwithstanding any choice of law provision
contained in, or law of any other jurisdiction applicable to, any of the
documents, or any such other document, or any issuer or guarantor, including the
State of New



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Jersey, the Netherlands, Belgium or the European Union. We express no opinion as
to any local laws or ordinances.

            In connection with our opinions with respect to any issuer or
guarantor organized under a Foreign Law or with respect to the validity, binding
nature or enforceability against any of them of any documents signed by any of
them or to which any of them is bound, no opinion is expressed that a remedy
will be available with respect to each covenant or agreement of such party or
that any such covenant or agreement will otherwise be given effect, or that any
remedy expressly provided for in any such document will be given effect as
stated, and we further assume that:


            (a) insofar as any obligation or right is to be performed in, or is
otherwise affected by the laws of, any jurisdiction other than the federal laws
of the United States and the laws of the State of New York, the performance of
any such obligation and the exercise of any such right would not be illegal or
ineffective under the laws of that jurisdiction;


            (b) any law, other than the federal laws of the United States and
the laws of the State of New York, which may apply to the formation, validity,
binding nature or enforceability of a contract or to any of the documents (or
the transactions contemplated thereby) would not be such as to affect any
opinion stated in this letter;

            (c) all of the conditions necessary under any of the Foreign Laws
for the formation, validity, binding nature and enforceability of a contract
have occurred, including its due authorization, execution and delivery and the
existence of adequate consideration;

            (d) the Units, to the extent of the obligations of the Dutch Issuer,
and the Dutch Notes, would be treated by all courts in the Netherlands as
constituting the legal, valid and binding obligations of the Dutch Issuer
enforceable against the Dutch Issuer in accordance with their respective terms,
and such documents are in proper form for their enforcement in such Dutch
courts.

            (e) the Guarantee of Phibro Belgium would be treated by all courts
in Belgium as constituting the legal, valid and binding obligation of Phibro
Belgium enforceable against Phibro Belgium in accordance with its terms, and
such Guarantee is in proper form for its enforcement in such courts;


            (f) the choice of New York internal law (without regard to conflict
of laws principles) as the law governing the documents would be upheld as a
valid choice of law by the courts of the respective jurisdictions of
organization of the Dutch Issuer and Phibro Belgium, and applied by those courts
in relation to the documents as the governing law thereof; and



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            (g) neither the execution, delivery or performance of any foreign
collateral documents, the issuance of Units by the Dutch Issuer or the Dutch
Notes or the consummation of any transactions contemplated therein or by the
Indenture conflicts with, violates, constitutes a breach of or a default (with
the passage of time or otherwise) under, requires the consent of any person
under, results in the imposition of a lien on any assets of any issuer or
guarantor (except for liens created pursuant to the collateral documents, also
as to which no opinion is expressed herein) or results in acceleration of
indebtedness under or pursuant to (i) any of the charter documents of the Dutch
Issuer or Phibro Belgium, (ii) any indenture, lease, note, contract or other
agreement or instrument which is binding on the Dutch Issuer or Phibro Belgium
or any of its properties (other than any thereof filed as an exhibit to the
Registration Statement, or (iii) any statute, law, rule or regulation of the
Netherlands, Belgium or European Union or any political subdivision thereof
binding on any issuer or guarantor or any of its properties, or any judgment,
order or decree of a Dutch, Belgium or European Union court or administrative or
regulatory body.

            Based upon and subject to the foregoing and the limitations,
assumptions, qualifications and exceptions set forth herein, we are of the
opinion that the New Securities have been duly authorized by the Company and the
Designated Guarantors, and when (i) the Registration Statement becomes effective
under the Act and the Indenture has been qualified under the Trust Indenture Act
of 1939, as amended, and (ii) the New Securities have been duly executed and
authenticated in accordance with the terms of the Indenture and have been
delivered upon consummation of the Exchange Offer against receipt of Old
Securities surrendered in exchange therefor in accordance with the terms of the
Exchange Offer, assuming the due authorization, execution and delivery of the
New Dutch Notes by the Dutch Issuer and of the guarantee thereof by Phibro
Belgium, the New Securities will constitute valid and binding obligations of the
Company and each of the Designated Guarantors, enforceable against the Company
and each of the Designated Guarantors in accordance with their respective terms.

            The opinion set forth above is qualified as follows:

            A. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture and under the
Guarantees, are subject to and may be limited or affected by (i) bankruptcy,
insolvency, reorganization, moratorium or similar laws now or hereafter in
effect affecting creditors' rights generally (including, without limitation,
Section 548 of the United States Bankruptcy Code, state fraudulent transfer laws
and other similar laws relating to fraud on creditors), and (ii) general
principles of equity, regardless of whether such validity or enforceability of
obligations or availability of rights and remedies is considered in a proceeding
in equity or at law.

            B. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture and the Guarantees, may
be further limited by other laws and judicial decisions with respect to or
affecting remedial or procedural provisions contained in



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such documents, but in our judgment and subject to the other qualifications set
forth in this letter, such other laws and judicial decisions do not render the
Indenture invalid as a whole or substantially interfere with realization of the
principal benefits intended to be provided thereby.

            C. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture, including the
Guarantees under the Indenture, may be further limited by other laws and
judicial decisions with respect to the enforceability of any waiver granted
under Section 6.04 of the Indenture.

            We hereby consent to the filing of this opinion with the Commission
as an exhibit to the Registration Statement. We also consent to the reference to
our firm under the caption "Legal Matters" in the Registration Statement. In
giving this consent, we do not thereby admit that we are included in the
category of persons whose consent is required under Section 7 of the Act or the
rules and regulations of the Commission.

                                   Very truly yours,


                                   /s/ Golenbock Eiseman Assor Bell & Peskoe LLP