Abstrakt: |
An outbreak of aflatoxicosis is reported in calves in Iran. Aflatoxicosis is caused by aflatoxins and is the most important disease resulting from ingestion of feed contaminated with Aspergillus spp. Two hundred 4- to 10-month-old male Holstein calves of approximately 150 kg were kept in a farm and were fed a ration consisting of alfalfa hay and sunflower cakes. A total of 35 calves (17%) died 4 months after presenting a disease characterised by general unthriftiness, diarrhoea and death. Necropsy findings included firm, pale livers and hydrothorax. Lymphopenia, monocytosis, high levels of serum sorbitol dehydrogenase (SDH), alkaline phosphatase (ALP) and SGOT in the serum and congestion, necrosis, fatty change and megalocytosis in the necropsied livers were found on laboratory examination. Reverse transcription-polymerase chain reaction detected bovine viral diarrhoea (BVD) virus genome in the affected calves. Toxicogenic species of Aspergillus (mainly A. flavus) grew in the culture from sunflower feeds. The analysis of the feed revealed 1,130 μg of AFB/kg. A diagnosis of aflatoxicosis due to the immunosuppressive effects of the BVD-MD infection was made based on the characteristic clinical signs, pathology, virology, haematology, biochemistry and mycology, and on the presence of high levels of aflatoxin B in the sunflower fed to the calves. Providing aflatoxin-free feeds to calves prevented further clinical cases. This report demonstrates the need for careful quality control of feed products and the susceptibility of immunosuppressive calves to the effects of aflatoxins. [ABSTRACT FROM AUTHOR] |