Effect of Tenuazonic Acid on Young Chickens

Abstract

Tenuazonic acid, a toxic metabolite produced by various Alternaria species was found to be toxic to young chickens. Tenuazonic acid given in the diet at 10 μg of toxin/g of feed or by daily esophageal intubation at the levels of 1.25 or 2.50 mg of toxin/kg of body weight to 3-week-old broilers for 3 weeks resulted in decreased weight gain and lowered feed efficiency during the second and third weeks of toxin administration. Although no morbidity or mortality was noted in chickens receiving toxin by either route, marked gross and microscopic lesions were evident in various tissues of birds receiving toxin by either method. The majority of chickens receiving toxin by esophageal intubation developed either all or several of the following lesions: enlarged and mottled spleen, slight erosions of the gizzard, hemorrhage in the intestinal lumen and on the surface of the heart, edema of the myocardium, and hemorrhage with bruising in the musculature of the thigh. Broilers receiving toxin in the feed showed no gross hemorrhages, although gizzard erosion with pale and mottled spleens was evident. Microscopically, congestion of blood vessels and hemorrhage was evident in all grossly affected tissues as well as in the kidneys and liver. One-week-old White Leghorns receiving either 1.25 or 2.50 mg toxin/kg body weight daily by esophageal intubation for 3 weeks also had lower weight gain and feed efficiency as well as similar pathologic changes as seen with broilers receiving toxin by esophageal intubation.