Mycotoxicoses I. Relationship of Toxic Fungi to Moldy-Feed Toxicosis in Poultry

Abstract

Fungi isolated from feed samples collected where poultry hemorrhagic syndrome was present formed toxic substances when grown on sterile grain under laboratory conditions. Pathologic findings in chicks affected acutely included hemorrhages and congestion in many tissues, and distinct changes in liver and kidneys. In chronic cases, the major changes were in the liver, kidneys, and bone marrow. The marrow showed depletion of the erythropoetic centers, hypoplasia of the myelopoetic centers, and lymphocytic foci with many fat cells. Birds exposed under field conditions developed an acute toxicosis initially characterized by depression and diarrhea, and subsequently by hemorrhages and congestion in many tissues. As the fungi continued to proliferate and form toxic substances, both acute and chronic forms of toxicosis were observed in the same flock. The primary gross and histopatho-logic findings closely resembled those of the battery birds. Under field conditions, fungal growth in the feed spilled in the litter became evident at 10 days. Up to the 4th week, the fungi present in the inoculum prevailed. Thereafter, their relative numbers rapidly decreased. Conversely, by the 4th week, a Scopulariopsis fungus became evident, and predominated from the 6th week until the experiment was terminated, at 12 weeks. A decline in over-all clinical and pathologic appearance of the toxicosis appeared to be concomitant with the proliferation of the Scopulariopsis. Dermal toxicity on rabbits of ether extracts prepared from feed spilled in the litter coincided with the clinical and pathologic observations in chicks.