<PAGE>   1
                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

(MARK ONE)
[X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
          THE SECURITIES EXCHANGE ACT OF 1934.

FOR THE QUARTERLY PERIOD ENDED MARCH 31, 1999

                                       OR

[ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
          THE SECURITIES EXCHANGE ACT OF 1934

FOR THE TRANSITION PERIOD FROM _______ TO _______

Commission file number:  333-49289


                           SOUTHERN FOODS GROUP, L.P.
             ------------------------------------------------------
             (Exact name of registrant as specified in its charter)

               DELAWARE                                     75-2571364    
    -------------------------------                     -------------------
    (State or other jurisdiction of                      (I.R.S. Employer
     incorporation or organization)                     Identification No.)

   3114 SOUTH HASKELL, DALLAS, TEXAS                          75223       
----------------------------------------                    ----------
(Address of principal executive offices)                    (Zip Code)

                                 (214) 824-8163
              ----------------------------------------------------
              (Registrant's telephone number, including area code)

                                 NOT APPLICABLE
         ---------------------------------------------------------------
              (Former name, former address and former fiscal year,
                         if changed since last report.)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes  X   No     .
                                      -----   -----

<PAGE>   2

                         PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

                           SOUTHERN FOODS GROUP, L.P.

                                 BALANCE SHEETS

                                 (in thousands)


<TABLE>
<CAPTION>
                                                            March 31,      December 31,
                                                              1999            1998     
                                                          ------------    ------------
                           ASSETS                          (unaudited)

<S>                                                       <C>             <C>
Current assets:
     Cash and cash equivalents .........................  $      4,708    $      8,827
     Accounts receivable, net ..........................       106,469          92,209
     Inventories .......................................        33,804          34,205
     Prepaid expenses and other assets .................         3,742           4,846
                                                          ------------    ------------
               Total current assets ....................       148,723         140,087
                                                          ------------    ------------

Property, plant and equipment, at cost .................       219,859         213,597
     Less:  accumulated depreciation and amortization ..       (41,892)        (37,312)
                                                          ------------    ------------
                                                               177,967         176,285
                                                          ------------    ------------

Goodwill, net of accumulated amortization ..............       231,323         229,512
Trademarks and licenses, net ...........................       101,004         101,529
Deferred financing costs, net ..........................        11,612          11,929
Other assets ...........................................         5,049           2,066
                                                          ------------    ------------
               Total assets ............................  $    675,678    $    661,408
                                                          ============    ============

               LIABILITIES AND PARTNERS' EQUITY

Current liabilities:
     Raw milk accrual ..................................  $     42,239    $     32,035
     Accounts payable ..................................        46,735          46,464
     Accrued expenses ..................................        48,396          47,845
     Current portion of long-term debt .................         1,209             600
                                                          ------------    ------------
               Total current liabilities ...............       138,579         126,944

Long-term debt .........................................       310,803         313,608
Other long-term liabilities ............................        11,849          10,784
Commitments and contingencies ..........................            --              --

Partners' equity .......................................       214,447         210,072
                                                          ------------    ------------
               Total liabilities and partners' equity ..  $    675,678    $    661,408
                                                          ============    ============
</TABLE>

      The accompanying notes are an integral part of these financial statements.


                                     Page 2

<PAGE>   3
                           SOUTHERN FOODS GROUP, L.P.

                              STATEMENTS OF INCOME

                           (unaudited - in thousands)


<TABLE>
<CAPTION>
                                                     For the three months
                                                        ended March 31,           
                                                ----------------------------
                                                    1999            1998    
                                                ------------    ------------

<S>                                             <C>             <C>         
Net sales ...................................   $    330,604    $    272,025
Cost of sales ...............................        258,074         205,751
                                                ------------    ------------

                                                      72,530          66,274
                                                ------------    ------------

Selling, distribution and general
   and administrative expenses ..............         54,214          49,932
Amortization of goodwill and other
   intangible assets ........................          3,763           3,685
                                                ------------    ------------

Income from operations ......................         14,553          12,657

   Interest expense .........................          7,327           8,124
   Other (income) expense, net ..............           (284)           (370)
                                                ------------    ------------

Net income ..................................   $      7,510    $      4,903
                                                ============    ============
</TABLE>


   The accompanying notes are an integral part of these financial statements.


                                     Page 3
<PAGE>   4

                           SOUTHERN FOODS GROUP, L.P.

                         STATEMENTS OF PARTNERS' EQUITY

                           (unaudited - in thousands)


<TABLE>
<CAPTION>
                                                 Preferred                Common        
                                                ------------    ---------------------------
                                                  Limited         General        Limited
                                                  Partner         Partner        Partner          Total        
                                                ------------    ------------   ------------    ------------

<S>                                             <C>             <C>            <C>             <C>         
Partners' equity, December 31, 1998 .........   $    201,514    $        419   $      8,139    $    210,072
     Conversion of common equity
         to preferred .......................          1,700              --         (1,700)             --
     Distributions ..........................         (1,437)             --         (1,698)         (3,135)
     Net income .............................          6,474              10          1,026           7,510
                                                ------------    ------------   ------------    ------------
Partners' equity, March 31, 1999 ............   $    208,251    $        429   $      5,767    $    214,447
                                                ============    ============   ============    ============
</TABLE>


   The accompanying notes are an integral part of these financial statements.


                                     Page 4

<PAGE>   5

                           SOUTHERN FOODS GROUP, L.P.

                            STATEMENTS OF CASH FLOWS

                           (unaudited - in thousands)

<TABLE>
<CAPTION>
                                                      For the three months ended    
                                                     ----------------------------
                                                       March 31,       March 31,
                                                         1999            1998     
                                                     ------------    ------------

<S>                                                  <C>             <C>         
Net cash provided by operating activities ........   $     12,669    $     13,452
                                                     ------------    ------------

Cash flows from investing activities:
Acquisitions, net of cash acquired ...............         (4,800)             --
Additions to property, plant and equipment .......         (6,657)         (2,239)
Decrease in other assets .........................             --             381
                                                     ------------    ------------

Net cash used in investing activities ............        (11,457)         (1,858)
                                                     ------------    ------------

Cash flows from financing activities:
Repayments - long-term debt ......................           (196)           (596)
Net repayments - revolving credit facility .......         (2,000)        (13,500)
Partner distributions - preferred equity .........         (1,437)             --
Partner contributions - common equity ............             --             119
Partner distributions - common equity ............         (1,698)           (362)
                                                     ------------    ------------

Net cash used in financing activities ............         (5,331)        (14,339)
                                                     ------------    ------------

Net decrease in cash .............................         (4,119)         (2,745)
Cash at beginning of period ......................          8,827           4,747
                                                     ------------    ------------

Cash at end of period ............................   $      4,708    $      2,002
                                                     ============    ============

Cash paid during the period for interest .........   $      9,374    $     11,145
</TABLE>



   The accompanying notes are an integral part of these financial statements.


                                     Page 5

<PAGE>   6

                           SOUTHERN FOODS GROUP, L.P.
                          NOTES TO FINANCIAL STATEMENTS



1.   BASIS OF PRESENTATION

     The consolidated financial statements of Southern Foods Group, L.P. ("SFG"
or the "Partnership") included herein have been prepared by the Partnership,
without audit, pursuant to the rules and regulations of the Securities and
Exchange Commission ("SEC"). In the opinion of management, the information
furnished reflects all adjustments, consisting only of normal recurring
adjustments, which are necessary for a fair presentation of the results of the
interim periods. Certain information and footnote disclosures normally included
in financial statements prepared in accordance with generally accepted
accounting principles have been condensed or omitted pursuant to the SEC's rules
and regulations. However, management believes that the disclosures contained
herein are adequate to make the information presented not misleading. The
results of operations for the periods presented are not necessarily indicative
of the results to be expected for the full year. These consolidated financial
statements should be read in conjunction with the financial statements and the
notes thereto included in the Partnership's 1998 Annual Report on Form 10-K. No
significant accounting changes have occurred during the three months ended March
31, 1999.

2.   INVENTORIES

     A summary of inventories is as follows (in thousands):

<TABLE>
<CAPTION>
                                               March 31,         December 31,
                                                 1999                1998    
                                            --------------      -------------
<S>                                         <C>                 <C>          
          Finished goods.................   $       17,731      $      16,551
          Packaging and supplies.........            1,358              4,709
          Raw materials..................           13,682             11,896
          Truck parts....................            1,033              1,049
                                            --------------      -------------
                                            $       33,804      $      34,205
                                            ==============      =============
</TABLE>

3.   EQUITY TRANSACTIONS

     In accordance with SFG's partnership agreement, the Partnership made tax
payment distributions to the management owner totalling $1.7 million for the
three months ended March 31, 1999. As also required by the partnership
agreement, the Partnership converted equal amounts of DFA's limited partner
common equity to Series E Preferred Interests with a cumulative return of 10%.
In January 1999, the Partnership distributed $1.4 million in payment of
preferred return on the Series D Preferred Interests. The total stated value of
Preferred Interests outstanding at March 31, 1999 was $270.8 million, including
unpaid preferred returns.

4.   STATEMENTS OF FINANCIAL ACCOUNTING STANDARDS NOT YET ADOPTED

     In June 1998, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 133, "Accounting for Derivative Instruments
and Hedging Activities" ("SFAS 133"). This new standard is effective for fiscal
years beginning after June 15, 1999 (January 1, 2000 for the Partnership). SFAS
133 requires that all derivative financial instruments be recorded on the
balance sheet at their fair value. Changes in the fair value of derivatives are
recorded each period in current earnings or other comprehensive income,
depending on whether a derivative is designated as part of a hedge transaction
and, if it is, the type of hedge transaction. The Partnership has not yet
adopted this new standard or completed its evaluation of the impact of such
adoption.



                                     Page 6

<PAGE>   7

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
         OF OPERATIONS

                                     GENERAL

     The Partnership owns 27 facilities which process and distribute fluid milk
products, cultured products, ice cream products, fruit juices and drinks and
other dairy related products. The majority of the Partnership's sales are from
fluid milk products, which include fresh packaged milk and chocolate milk in
whole, reduced fat and fat-free varieties, whipping cream, half-and-half and
buttermilk. These products are produced and marketed primarily under the
Schepps, Oak Farms, Meadow Gold, Mountain High, Viva, Foremost, Flav-O-Rich,
Borden, Barbe's Dairy and Brown's Velvet Dairy brand names, as well as various
private labels. The Partnership produces cultured products, such as sour cream,
cottage cheese and yogurt, as well as ice cream and fruit juices and drinks
under its brand names, various private labels and third-party labels. The
Partnership also distributes cultured products, fruit juices and drinks, ice
cream products and other dairy related products such as cheese, eggs, butter and
non-dairy creamers purchased from third parties.

     The comparability of sales and gross profit between the quarters ended
March 31, 1999 and 1998 are significantly impacted by an increase in raw milk
costs. The average federal market order price of Class I fluid milk (raw milk)
increased over 20% in the first quarter of 1999 as compared to the same quarter
of the prior year. The Partnership experienced higher sales as the higher raw
milk costs are generally passed on to customers. However, the corresponding
increase in cost of sales results in a decrease in the gross profit percentage.
The comparability of results between quarters is also impacted by the
acquisitions of the dairy and juice processing operations of Excelsior Dairy in
Hawaii in July 1998, the acquisition of the dairy processing plant and
distribution operations in Huntsville, Alabama from Dean Foods Company in August
1998, and the acquisition of the dairy operations of Haleakala Dairy in Hawaii
in January 1999.

                              RESULTS OF OPERATIONS

Quarter Ended March 31, 1999 Compared to the Quarter Ended March 31, 1998

     The Partnership's net sales were $330.6 million for the quarter ended March
31, 1999, an increase of $58.6 million, or 22%, over the first quarter of 1998.
This increase is due primarily to the increase in raw milk cost which resulted
in higher average product prices. Net sales also increased due to additional
sales volumes from the acquired businesses, and growth in the Partnership's
existing and new customer base.

     The Partnership's gross profit was $72.5 million for the quarter ended
March 31, 1999, an increase of $6.3 million, or 9%, over the quarter ended March
31, 1998. The increase in gross margin is attributable to the increase in sales
volume. The decrease in the gross profit percentage is due to the increase in
raw milk costs.

     The Partnership's selling, general and administrative expenses of $54.2
million for the quarter ended March 31, 1999 were $4.3 million, or 9%, higher
than the same quarter of 1998. The increase is attributable primarily to the
acquired businesses, along with the general increase in selling activity.

     Interest expense during the first quarter of 1999 decreased $.8 million, or
10%, from the first quarter of 1998 due to lower average interest rates and a
decline in average debt outstanding.


                                     Page 7

<PAGE>   8

                         LIQUIDITY AND CAPITAL RESOURCES

     Cash provided by operating activities of $12.7 million for the quarter
ended March 31, 1999 was $.8 million lower than the quarter ended March 31,
1998, due primarily to decreased cash provided by working capital changes. Cash
and cash equivalents on hand at March 31, 1999 were $4.7 million compared to
$8.8 million at December 31, 1998.

     Cash used in investing activities for the quarter ended March 31, 1999 of
$11.5 million was $9.6 million higher than the quarter ended March 31, 1998 due
to the acquisition of Haleakala Dairy for $4.8 million in January 1999 and an
increase in capital expenditures of $4.4 million.

     Cash used in financing activities was $5.3 million for the quarter ended
March 31, 1999, primarily as a result of the net repayment of revolving loans of
$2.0 million and distributions to partners of $3.1 million. Cash used in
financing activities of $14.3 million for the quarter ended March 31, 1998 was
primarily a result of net repayments of revolving loans of $13.5 million.

     The Partnership's total debt at March 31, 1999 was $312.0 million. The
$130.8 million of the Partnership's senior subordinated notes (the "Notes")
which remain outstanding bear interest at a rate of 9 7/8%, payable
semi-annually each March 1 and September 1, and mature September 1, 2007. The
term loan portions of the Partnership's Senior Bank Facilities consist of
borrowings under two tranches, Tranche A for $73.2 million and Tranche B for
$87.3 million. Both tranches bear interest at variable rates, which weighted
average rates were 7.03% and 8.03% for Tranche A and Tranche B, respectively, at
March 31, 1999. At March 31, 1999, $20.0 million of revolving loans and $0.1
million of letters of credit were outstanding under the Partnership's $60
million revolving credit facility.

     Interest payments on the Notes and on the Senior Bank Facilities represent
significant liquidity requirements for the Partnership. The Partnership
anticipates that the Notes will require annual interest payments of
approximately $12.9 million and the Senior Bank Facilities will require
substantial interest payments based on the unamortized loan balance and variable
interest rates in effect (approximately $13.6 million annually based on March
31, 1999 balances and applicable interest rates). In addition to its debt
service obligations, the Partnership will require liquidity for capital
expenditures and working capital needs. Management believes that the cash flow
generated from its operations, together with amounts available under the
revolving credit facility, should be sufficient to fund its debt service
requirements, working capital needs, anticipated capital expenditures and other
operating expenses. The Partnership's future operating performance and ability
to service or refinance the Notes and to extend or refinance the Senior Bank
Facilities will be subject to future economic conditions and to financial,
business and other factors, many of which are beyond the Partnership's control.

     The Senior Bank Facilities and the Notes impose restrictions on the
Partnership's ability to make capital expenditures and limit the Partnership's
ability to incur additional indebtedness. Such restrictions, together with the
highly leveraged nature of the Partnership, could limit the Partnership's
ability to respond to market conditions, to provide for unanticipated capital
investments or to take advantage of business or acquisition opportunities. The
covenants contained in the Senior Bank Facilities and the Notes also, among
other things, limit the ability of the Partnership to dispose of assets, repay
indebtedness or amend other debt instruments, pay distributions, create liens on
assets, enter into sale and leaseback transactions, make investments, loans or
advances and make acquisitions.

     In 1997 and 1998, the Partnership began to utilize interest rate collars
and swaps to manage interest rate exposures. The principal objective of such
contracts is to reduce the impact of changes in interest rates on its variable
rate debt. The Partnership does not utilize financial instruments for trading or
other speculative purposes. Swap agreements are contracts to exchange variable
rates for fixed rate payments periodically over the life of the agreements
without the exchange of the underlying notional amounts. The notional amounts of
interest rate agreements are used to measure interest to be paid or received.
The Partnership makes interest payments on the Senior Bank Facilities based on
the floating rate plus the 


                                     Page 8

<PAGE>   9

applicable margin, and then either makes a payment to or receives a payment from
the counterparty to the swap agreement based on the related notional amount and
the difference between the fixed swap rate and the applicable floating rate.

     In January 1998, in order to fix the interest rates on the majority of the
Partnership's bank debt, the Partnership entered into various interest rate swap
agreements. The fixed LIBOR rate under these agreements ranges between 5.565%
and 5.63%. These agreements have an aggregate initial notional amount of $127
million, which declines annually over a five-year period to a final aggregate
notional amount of $23 million, and are cancellable at the counterparty's option
at the end of three or four years, based on the individual agreement. The
Partnership also has an interest rate collar with a notional amount of $28.0
million and a LIBOR rate cap of 7% and a floor of 5.65%. This agreement expires
in October 2000.

     The Partnership is involved in certain threatened and pending legal matters
in the ordinary course of business. Although neither the outcome of these
proceedings nor the effect of such outcome can be predicted with certainty, in
the opinion of management, the outcome of these matters should not have a
material adverse effect on the financial condition or results of operations of
the Partnership.

YEAR 2000 ISSUES

     The information provided below constitutes a "Year 2000 Readiness
Disclosure" for purposes of the Year 2000 Information and Readiness Disclosure
Act.

     The Partnership is continuing the process of conducting an internal review
of its computer systems to identify systems that could be affected by the "Year
2000" issue. The Year 2000 issue is the result of computer programs being
written using two digits rather than four to define the applicable year. Any of
the Partnership's programs that have time-sensitive software may recognize a
date using "00" as the year 1900 rather than the year 2000. This could result in
a major system failure or miscalculations.

     The Partnership's initiatives to minimize failures of its electronic
systems to process date sensitive information in the Year 2000 and beyond
include efforts to identify all mission critical information technology (IT)
systems, such as financial and distribution applications, and non-IT systems
such as plant production systems, and remediate those systems which are
non-compliant. Identification of IT systems includes taking an inventory of all
mission critical computer hardware and software and testing these systems for
Year 2000 compatability. Those systems that are not Year 2000 compliant will be
repaired or replaced as necessary. The Partnership's Year 2000 initiatives also
include identifying critical vendors and communicating with those vendors
regarding their Year 2000 readiness. These initiatives are underway.
Additionally, remediation efforts have been undertaken on systems that have been
identified as non-compliant. Utilizing internal resources to identify and assess
needed Year 2000 remediation, the Partnership currently anticipates that its
Year 2000 identification, assessment, remediation and testing efforts will be
completed by December 31, 1999.

     The Partnership has begun, but not yet completed, a comprehensive analysis
of the operational problems and costs (including loss of revenues) that would be
reasonably likely to result from the failure by the Partnership and certain
third parties to complete efforts necessary to achieve Year 2000 compliance on a
timely basis. The Partnership faces the risk that third-parties which the
Partnership relies upon for products or services will not be Year 2000 ready.
Services provided by these parties include power, telecommunications and public
utilities. Products include raw materials used in the processing or distribution
of the Partnership's products. The Partnership will also be reliant upon the
proper functioning of its banks for cash management services, and customers must
be able to receive products and process information for invoicing and payment. A
failure in any of these areas by third parties could result in the Partnership's
inability to process and deliver its products to customers, or to exchange
information required for the Partnership to receive or make payments. The
Partnership also faces the risk that third parties could confirm their systems
or products as being Year 2000 ready when they actually are not. The Partnership
continues the process of identifying these risks and will include, where
possible, mitigation of these risks in its contingency plan, which should be
substantially completed by the end of the third quarter of 1999.


                                     Page 9

<PAGE>   10

     The Partnership does not anticipate that the total costs related to its
Year 2000 compliance efforts will be material to its financial position.
However, given the complexity of the Year 2000 issue, the impact on business
operations due to failure by the Partnership to achieve compliance or failure by
third parties to achieve compliance, which the Partnership cannot control, could
adversely affect the Partnership's results of operations.

     Even if the Partnership acts in a timely manner to complete all of its
assessments and identify, develop and implement remediation plans believed to be
adequate, some problems may not be identified or corrected in time to prevent
material adverse consequences to the Partnership. The discussion above regarding
estimated completion dates, costs, risks and other forward looking statements
regarding Year 2000 is based on the Partnership's best estimates given
information that is currently available, and is subject to change. As the
Partnership continues to progress with its Year 2000 initiatives, it may
discover that actual results will differ materially from these estimates.

Uncertainties and Disclosure Regarding Forward-Looking Statements

     Certain statements in this report are "forward looking statements" within
the meaning of the Private Securities Litigation Reform Act of 1995. Forward
looking statements include all statements other than those of historical fact.
Those statements may be found in Management's Discussion and Analysis of
Financial Condition and Results of Operations. These statements involve risks
and uncertainties which may cause actual results to differ materially from the
forward looking statements. Among the risks or uncertainties faced by the
Partnership are heightened competition, including specifically the
intensification of price competition; adverse state and federal legislation and
regulation; loss of key executives; general economic and business conditions if
they are less favorable than expected; unanticipated changes in industry trends;
the ability of the Partnership to sustain, manage or forecast its growth; the
entry of new competitors and the development of new products or services by new
and existing competitors; failure to obtain new customers or failure to retain
existing customers; the inability to carry out marketing and sales plans; the
loss of significant suppliers; business disruptions; changes in business
strategy or development plans; liability and other claims asserted against the
Partnership; the ability to attract and retain qualified personnel; and other
statements made in this report may include additional factors which could
adversely impact the Partnership's business and financial performance. Moreover,
the Partnership operates in a very competitive and rapidly changing environment.
New risk factors emerge from time to time and it is not possible for management
to predict all such risk factors, nor can it assess the impact of all such risk
factors on the Partnership's business or the extent to which any factor, or
combination of factors, may cause actual results to differ materially from those
contained in any forward looking statements. Given these risks and
uncertainties, undue reliance should not be placed on forward looking statements
as a prediction of actual results.


                                     Page 10

<PAGE>   11

                           PART II. OTHER INFORMATION

ITEM 6.   EXHIBITS AND REPORTS ON FORM 8-K

     (a)  Exhibits

          10.42    Release of Claims, Confidentiality and Non-Competition 
                   Agreement
          10.43    Change in Control Agreement
          10.44    1998 Unit Appreciation Rights Plan
          10.45    Executive Medical Agreement
          27.1     Article 5 Financial Data Schedule

     (b)  Reports on Form 8-K

          None.

                                   SIGNATURES

          Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                            SOUTHERN FOODS GROUP, L.P.
                                            -----------------------------------
                                            (Registrant)


Date: May 14, 1999                          By: /s/  PATRICK K. FORD
                                            -----------------------------------
                                            Patrick K. Ford
                                            Chief Financial Officer, Secretary
                                            and Treasurer


                                     Page 11
<PAGE>   12

                               INDEX TO EXHIBITS

<TABLE>
<CAPTION>
Exhibit 
Number        Description
-------       -----------
<S>           <C>
 10.42        Release of Claims, Confidentiality and Non-Competition Agreement
 10.43        Change in Control Agreement
 10.44        1998 Unit Appreciation Rights Plan
 10.45        Executive Medical Agreement
 27.1         Article 5 Financial Data Schedule
</TABLE>