[Changes in metabolic indicators in cattle by season of the year].

The study was aimed at informing about the results of metabolic trials in large cattle stocks for the period from 1977 to 1980, particularly in view of the dynamics of changes in different metabolic parameters in each year season. The histogram method of statistical evaluation was used. Attention is drawn to the prevailing risk factors in each season and it is possible to investigate the general trend of the rise of new metabolic disorders, or suppression of older ones, in large cattle stocks. The risk metabolic factors of each season can be derived from the results. The summer season is characterized by the tendency to metabolic and respiratory acidosis, by the highest elimination of calcium combined with potassium stress, and by a lack of sodium ions. In the autumn the animals show a more pronounced form of metabolic and respiratory acidosis, not always sufficiently compensated; the liver is overloaded, there is a tendency to hypocalcaemia, and ketosis occurs more frequently, often very pronounced. In winter the acid-base balance of blood improved, acidosis is compensated more intensively by the renal route, calcium is increasingly eliminated in the urine, the overload on liver function is at its maximum, and ketosis occurs most frequently. The spring findings included increased elimination of calcium with the urine, the lowest Ca X P product over the whole year (this is in a high correlation with the higher activities of the ALP enzyme). the highest load of nitrogen compounds and worsened haemogenesis. It can be stated that the mentioned results represent some improvement in the metabolic profile as compared with earlier studies. The situation in enzyme activities can be regarded as a factor of deterioration: high activities of alkaline phosphatase documenting a tension in the metabolism of calcium and phosphorus, and increasing occurrence of chronical overloading of liver function, particularly in winter.