Studies on Cyanide and Nitrate Contents in Grasses

Abstract

The cyanide and nitrate contents in 24 kinds of grasses collected from Pakchong Animal Nutrition and Research Center, Nakorn Rajasima province during summer month are analysed. It was found that the cyanide contents varied from 0.0872 ppm to 77.24 ppm. The greatest amount is found in Sorghum halepense while the smallest in Digitaria sp. The second and third richest in cyanide are Sorghum almum and Digitaria decumbens with the cyanide content of 44.21 ppm and 29.90 ppm respectively. The cyanide contents in all kind of grasses examined are less than 200ppm and are safe for grazing. However, safety depends on the kind and the amount of grasses the animal grazes in a day with a special precaution on Sorghum halepense and Sorghum almum which contain cyanide in the highest level. It was also found that the nitrate contents varied from 24 ppm to 416 ppm The greatest amount was found in Panicum coloratum and the smallest in Eragrostes superb. The second and third richest in nitrate are Digitaria sp. And Digitaria decumbens with the nitrate content of 312 ppm and 256 ppm respectively. The nitrate contents in all kind of grasses examined are also safe for grazing. There is no relationship between the cyanide and nitrate contents in the grasses under study. The grass that is rich in cyanide may contain a small amount of nitrate whereas the grass with a small amount of cyanide may contain a large amount of nitrate.