HERD HEALTH
PIH-93
pork industry handbook
COOPERATIVE EXTENSION SERVICE • PURDUE UNIVERSITY • WEST LAFAYETTE, INDIANA
Slaughter Checks—An Aid to Better Herd Health
Authors
Robert E. Hall, University of Wisconsin
LeRoy Biehl, University of Illinois
Kenneth Meyer, Purdue University
Reviewers
Norman P. Kendall, Canandaigua, New York
Richard Nash, Sharpsville, Indiana
Norman Underdahl, University of Nebraska
Willard L. Upchurch, Crossville, Tennessee
Diane Wallin, Milnor, North Dakota
Every pork producer needs a herd health program. This program should be determined by continuous monitoring of the health and production records necessary for efficient herd management. The producer, his veterinarian, and other professional advisors should update the program at least once a year.

A good herd health program includes a veterinarian to make on-farm inspections, conduct blood tests and other diagnostic procedures, examine cull breeding stock and market hogs at slaughter, evaluate production records, counsel, and make written recommendations to the management team producing pork.

An important resource, often overlooked but providing important health information, is animals sold for slaughter.

Purposes
The purposes of a slaughter test are to (1) look for abnormal tissues so that specific problems can be identified and (2) monitor the effect of drug use, vaccination programs, or management changes. With this information the producer can work toward eliminating or controlling disease problems. A slaughter check reveals disease information about your herd that may not be found during a farm visit or an occasional necropsy.

Respiratory Diseases
Chronic respiratory diseases in swine are common on many farms (Figure 1). Monitoring the lungs of a group of slaughter hogs gives better information on the extent of the lung damage and possible causes. For example, some hogs may go to market looking healthy but be infected with mycoplasma, pasteurella, bordetella, hemophilus, lung-worms, or migrating roundworm larvae, all of which can cause lung damage. The probable cause, extent of the lesions, and the number of pigs with lesions can be correlated with days to slaughter and feed efficiency records to form a plan for drug treatment, vaccination, or change in environment.
Atrophic Rhinitis
The severity of atrophic rhinitis (AR) can be determined by sawing across the snout and measuring the turbinate damage (Figure 2). This examination is the most accurate way to determine if AR is present in a herd. Only a small percentage of AR can be detected by visual observation in the live animal. Routine slaughter exams can be used to monitor any improvement from a vaccination program or a change in facilities or management.

Worm Control
The need to deworm, and the success of a deworming program, can be monitored by slaughter examination. The most common worm of swine is the large roundworm (Ascarid). In the hog, part of the life cycles of roundworm and kidneyworm involve migration through the liver. The number of white spots in the liver is an indication of the
Cooperative Extension Work in Agriculture and Home Economics, State of Indiana, Purdue University and U. S. Department of Agriculture Cooperating. H. A. Wadsworth, Director, West Lafayette, IN. Issued in furtherance of the Acts of May 8 and June 30, 1914. We adhere to the policy that all persons shall have equal opportunity and access to our programs and facilities.