The effects of amino acid supplementation and medication of salmonella pullorum in chicks

The widespread and sometimes indiscriminate use of drugs and medications has, in part, led to masking of the physiological and biochemical mechanisms involved in host parasite relationships in certain bacterial diseases. Additional knowledge is needed in relation to physiological alterations with emphasis on the metabolic disturbances within the host during infection. The literature suggests that certain infectious diseases can cause alterations in protein, carbohydrate and fat metabolism. The observations of Rettger (1909), indicating the presence of unabsorbed yolk in young chicks dying of pullorum disease, first suggested an impairment of metabolic processes. Although pullorum disease has been largely controlled by testing programs, there still exists a potential danger to the poultry industry from this disease. There is still no known treatment for pullorum disease in poultry that can guarantee complete recovery and control. Consequently, more needs to be known regarding host parasite relationships, drug action and therapeutic evaluation of drugs in its control. Furthermore, this knowledge might well be applied to other bacterial infections. Dubos (1955) has done much to renew the interest in the biochemical basis to infection. With the metabolic disturbances in mind, Ross et al. (1955a) and Dooley et al. (1956) reported some major alterations in the nitrogen metabolism of chicks clinically infected with Salmonella pullorum. Among this findings was the observation that certain free and bound amino acids in the blood serum were depleted during the course of infection. Subsequent supplementation of some of the depleted amino acids resulted in prolonging the survival time of the fatally infected chicks. Much work has been done with dietary protein levels and disease interrelationships. However, little has been reported with respect to individual amino acids and disease interaction. The study reported in this thesis was undertaken to explore the aspects of amino acid deficiencies; supplementation of serum deficient amino acids; and drug evaluation in search for a combined treatment that might be beneficial in treating chickens with pullorum disease.