Heavy Concentration Of Nitrate On Chou Moellier

Press, Volume CX, Issue 32391, 2 September 1970, Page 23

Heavy Concentration Of Nitrate On Chou Moellier

(N.Z. Press Association) WELLINGTON, Sep. 1. Leaves of chou moellier eaten by 36 cows that died on a Pihama, Taranaki, farm were found by a Wallaceville diagnostician to contain double tbe safe maximum level of nitrate. In a letter to a member of the New Zealand Press Association, the superintending veterinary investigation officer of the Wallaceville animal health laboratory of the Department of Agriculture (Mr D. F. L. Money) said that the report that tests at the centre had failed to reveal the cause of death was misleading. The history of these animals, as recorded by the owner's veterinary surgeon, was that, after grazing chou moellier through the autumn and winter, they broke through an electric fence from stumps to an area of second growth, which they ate from 2..00 p.m. to 2.45 p.m., on July 27, Mr Money said in his letter.

Between 3.00 p.m. and 5.30 p.m. 86 cows died and were carted away by a boiling down works operator, even before the veterinarian was consulted.

No post-mortem examinations were made, and no specimens were submitted to the Wallaceville laboratory. Five days after the deaths the veterinarian consulted the superintending veterinary investigation officer, Wallaceville, to say that he wished to send some of the chou moek lier for a cyanide estimation. He was told that cyanide was not a likely cause of the deaths, and that a nitrate estimation should be made. (Ruminant animals convert nitrate to nitride, and after absorbtion this converts haemoglobin to methaemoglobin, which is unable to carry oxygen to the tissues.) On August 10, Wallaceville reported that there was no cyanide in the leaves received, but that the nitrate level was nearly double the maximum safe level, Mr Money said. In the time that elapsed between the deaths and the collection of chou moellier nitrate levels could have decreased or increased, according to weather conditions. Laboratory examinations of animal specimens, especially blood were necessary to confirm that fatal nitrate poisoning had in fact occurred.