Biochemical changes in the rumen fluid and blood in cows fed large amount of grain food

Four experiments were performed in 4 cows which were fed large amount of grain feed. The food was given in a single dose or in gradually increasing doses and hay was excluded or retained in the diet. In 3 cows, symptoms of acid indigestion were observed, two of them recovered spontaneously and the third cow died on the 6th day after overeating 20 kg of ground grain barley. In these cows the following changes were found: a sudden decrease in the pH of the rumen fluid, accumulation of lactic acid in the rumen fluid and its increased concentration in the blood, increased serum inorganic phosphorus level and inereased calcium, magnesium and inorganic phosphorus concentrations in the rumen fluid.