Ammonia Toxicity in Cattle. I. Rumen and Blood Changes Associated with Toxicity and Treatment Methods2

Publisher Website
Google Scholar
Abstract
The toxicity of several cooked mixtures of grain and urea was tested using 26 rumen-fistulated, mature fasted cattle maintained on a 40% concentrate ration containing no urea for at least 7 days before each test. On the test day each animal was given, via a rumen cannula, enough product to provide .5 g urea per kilogram body weight. Rumen and jugular blood samples were taken at 30-min intervals. Ammonia toxicity, judged by appearance of definite muscle tetany was observed 125 times. No toxicity occurred in 119 trials. On the average, muscle tetany appeared after 52.8 minutes. Rumen pH and blood ammonia were positively correlated and rumen ammonia and blood urea were not correlated with toxicity. Apparently, high rumen ammonia concentrations may exist without producing toxicity if the ration is readily fermentable and lowers rumen pH below 7.4. Drenching animals showing toxic signs with acetic acid did not lower blood ammonia concentration during the first 120 min and 20% of the treated animals died. Emptying the rumen of animals showing toxic signs resulted in rapid decrease of blood ammonia concentration. In 100 trials all animals treated in this manner recovered in approximately 2 hr and then readily consumed hay and grain. Rapid evacuation of rumen contents is suggested as a method for treating ammonia toxicity. Copyright © 1976. American Society of Animal Science . Copyright 1976 by American Society of Animal Science

This publication has 2 references indexed in Scilit: