Nitrate poisoning was observed in Holstein calves raising for beef purpose in a dairy-farm of Gyeongbug province.
The results observed were summarized as follows:
1. These calves had ben fed mainly cornstalk, and a qualitative reaction by “dephenylamine blue test” for nitrate was positive in the serum of the affected calves and in the cornstalk provided.
2. In the clinical signs, the affected calves were suddenly recumbent without premonition and then dyspnea, followed by death. Death also occurred after inappetence, depression, dyspnea, cyanosis of mucous membrane, and terminal anoxic convulsions were observed.
3. In the macroscopical findings, the blood was dark- brown (chocolate in color) and more or less poor coagulative. Petechiae of epicardium, severe cloudy swelling of liver, cloudy swelling and hemorrhage of kidney, congestion and hemorrhae of spleen, congestion and edema of lung, and congestion af abomasum and small intestine were observed in these cases.
4. Microscopical changes observed in these cases were peripheral congestion of lobules, centrilobular necrosis and sinusoidal dilatation in liver, hydropic degeneration of hepatic cells, hemorrhage and edema of kidney, necrosis of convoluted tubular epithelium, and dilatation of Bowman´s spare and convoluted tubule. There were also congestion and hemorrhage of spleen, hemorrhage and edema of lung, cloudy swelling of myocardium, and congestion and hemorrhage of various organs.
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