Implementing a Feedlot Medicine Program
Regular inspection of all areas of the feedlot should be included in a feedlot health service. Credit for keen observation and a job well done along with recommendations for improvement in animal husbandry should be noted and recorded for discussion with personnel. Attention should be given particularly to the delivery of feed and water, the general well-being of cattle, and any unusual characteristics of each feeding pen. Many feedlot health problems can be prevented with excellent management.
Continued disease surveillance through regular necropsy examination of all dead cattle and regular observations of sick cattle are necessary. In colder climates, carcasses may freeze solid before the veterinarian is available. Conversely, in warmer climates, carcasses may decompose beyond usefulness. When distance prevents the consulting veterinarian from performing a necropsy on every animal that dies, a more accessible veterinarian may be employed. In many cases, feedlot personnel can be trained to recognize common postmortem lesions, take digital photographs of such lesions and send them to the consulting veterinarian, and collect tissues for potential analysis.
A key to management of disease in feedlots is a fast and accurate diagnosis. This requires a good surveillance system, a systematic plan to search for sick animals, appropriate facilities for examination and treatment, accurate identification of animals, and appropriate laboratory facilities, especially a necropsy service. Emphasis is placed on training and supervising feedlot employees in the detection and early treatment of sick cattle. Employees, particularly any personnel responsible for checking the cattle pens for sick cattle, should be given regular instruction in the clinical signs of common diseases. These include anorexia, depression, lameness or abnormal gait, stiff movement, coughing, nasal and ocular discharge, increased breathing rate, crusted muzzle, sunken eyes, rough hair coat, loose or very firm feces, abnormal abdominal fill, and straining. Cattle with these or other signs of illness are examined more closely in the hospital area and, if necessary, treated. In some feedlots, treated cattle are immediately returned to their original pens, whereas in others cattle are kept in hospital pens until they recover. Most animals that do not recover or that relapse after the first treatment are re-treated, although this decision depends on the nature of the disease and the economics involved. If an animal becomes chronically ill and chances of recovery are slim, it should be sold for slaughter if this is a viable option (after the appropriate withdrawal time) or, in the case of a calf, euthanized.
Pens from which sick animals are taken should be closely observed. A potential epidemic must be identified early so that pen-level intervention can be considered.
Despite its importance, pen surveillance is not highly reliable for the detection of sick feedlot animals, particularly calves in the first week after arrival. It is difficult to distinguish tired, gaunt calves that may have been weaned a few days earlier from calves in the early stage of acute, undifferentiated respiratory disease. As many as 50% of animals pulled from a pen of recently arrived calves will not show clinical signs of respiratory disease based on measurement of body temperature and a cursory clinical examination.
The veterinarian must specify procedures for the clinical management of sick cattle and provide a standard protocol that outlines specific treatments for disease syndromes, including drug dosages, treatment intervals, routes of administration, and withdrawal times. The protocol should be followed strictly by all personnel so that the success or failure of therapy can be evaluated accurately and that chances of creating food safety hazards are zero. The effectiveness of the treatment protocol should be evaluated regularly by determination of the response rates for the various treatment regimens. Failure to develop and implement appropriate treatment protocols often leads to the use of many different drugs indiscriminately, which then leads to excessive treatment costs and often an increase in the case fatality rate.