Part 1

Transcriber’s Notes

Obvious typographical errors have been silently corrected. Several tables have been divided with duplication of the first column because of their excessive width.

Italics are represented thus italic.

Issued March 17, 1911.

U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY.—BULLETIN 132. A. D. MELVIN, CHIEF OF BUREAU.

A BACTERIOLOGICAL STUDY OF HAM SOURING.

C. N. McBRYDE, M. D., Senior Bacteriologist, Biochemic Division.

WASHINGTON: GOVERNMENT PRINTING OFFICE. 1911.

THE BUREAU OF ANIMAL INDUSTRY.

Chief: A. D. MELVIN. Assistant Chief: A. M. FARRINGTON. Chief Clerk: CHARLES C. CARROLL. Animal Husbandry Division: GEORGE M. ROMMEL, chief. Biochemic Division: M. DORSET, chief. Dairy Division: B. H. RAWL, chief. Inspection Division: RICE P. STEDDOM, chief; R. A. RAMSAY, MORRIS WOODEN, and ALBERT E. BEHNKE, associate chiefs. Pathological Division: JOHN R. MOHLER, chief. Quarantine Division: RICHARD W. HICKMAN, chief. Zoological Division: B. H. RANSOM, chief. Experiment Station: E. C. SCHROEDER, superintendent. Editor: JAMES M. PICKENS.

LETTER OF TRANSMITTAL.

UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY, Washington, D. C., November 2, 1910.

SIR: I have the honor to transmit and to recommend for publication as a bulletin of this Bureau a paper entitled “A Bacteriological Study of Ham Souring,” by Dr. C. N. McBryde, senior bacteriologist in the Biochemic Division of this Bureau.

The souring of hams is a source of considerable loss in the meat-packing industry, and the cause of this trouble has heretofore been in doubt. Dr. McBryde’s paper presents the results of an exhaustive study of the subject, from which it appears that he has succeeded in discovering the true cause of the trouble. Besides a description of the experimental work the paper discusses methods of preventing the souring of hams and the proper disposal of those which have become affected.

Respectfully, A. D. MELVIN, Chief of Bureau.

Hon. JAMES WILSON, Secretary of Agriculture.

CONTENTS.

Page.

Introductory 7

Method of curing hams 8

Definition of souring 10

Classification of sour hams and location of sour areas 10

Method of detecting sour hams 12

Theories in regard to ham souring 12

Previous experimental work to determine cause of ham souring 13

The present experiments 14

Media employed 14

Method of procedure in examining hams 15